Washing our hands has become one major way to protect ourselves from Covid-19. However, ablutions have always had a central place in the practices and beliefs of many religious traditions. Christians perform baptism with water, in amounts varying from small sprinkles to larger vessels, to bring about purification, cleanliness, revival, and rebirth. Jesus’ washing the feet of his disciples as narrated in the Gospel makes the washing of feet an important practice in Christianity to promote cleanliness and is still carried out to this day. The Jewish tradition also has many instances of ablution where water is specifically used to promote cleanliness, including washing hands to reclaim or preserve purity and mikveh in which the feet or whole body is immersed in water.

The Islamic ablution, also known as “wudhu,” contains 24 washing movements to be carried out several times a day for the five daily prayers. If performed for all five prayers, it would consist of about 120 repeated actions as Muslims washed parts of their body.

A lover must undertake the required preparation to cleanse and beautify oneself before meeting with their Beloved. Likewise, a believer is required to wash specified parts of their body to stand before God in supplication, as instructed in Chapter Maidah of the Qur’an, verse 6: “O believers, when you stand for prayer, wash your faces, and your hands up to the elbows, and wipe your heads, and wash your feet up to the ankles. If you are unclean, bathe and purify your bodies fully. But if you are ill or in the middle of travelling or … you cannot find water, then take wholesome dust and wipe your faces and hands with that. For God does not wish to burden you, rather He desires to purify you and to complete His blessing and favor upon you so that, perhaps, you may be grateful” [5:6].

The spiritual cleansing that the act of wudhu provides is highlighted by the Prophet Muhammad (pbuh) in numerous hadiths, or prophetic sayings, which has been collected under The Book of Purification. While water literally cleans the face and limbs, with every pure intention to do wudhu, the water droplets that meet the body also wash away the minor sins that were committed by the hands, mouth, face, ears, and feet. The famous hadith that “cleanliness is half of faith” [Sahih Muslim, 223] can be interpreted as applying primarily to doing wudhu in one translation [Wudhu: Fiqh, Rules, Purification and Blessings, Qadri]. Therefore, to perfect the faith, to be cleansed of our mistakes continuously, God has given us a simple mechanism through which to be purified and recalibrated countless times in a day.

Many of us perform this pattern of washing with little thought. It has become a routine that we seldom consider a medical protection that we apply to our body. Besides its effects on the soul, washing also has wonderful effects on the body. Over fourteen hundred years ago, the Prophet (pbuh) advised ablution before going to bed. Interestingly, yoga experts in recent years have also started to encourage the washing of the legs, hands, arms, eyes, and the mouth before sleep with cool water for a deeper undisturbed sleep. This is not surprising considering the relief that comes with the touch of water on a busy day.

Three of our principal systems benefit from wudhu; the circulatory system, the immune system, and the electrostatic balance of the body. In this way, the health benefits from the ritual of washing are threefold…

Circulatory system

The circulatory system is a magnificent circuit of blood vessels between the heart and the tissues that make up every other system of the body. The systemic circulatory system circulates oxygenated blood from the heart to the tissues around the body and back to the heart, whilst the pulmonary circulatory system transports deoxygenated blood to the lungs for detoxification and returns clean blood to the heart. The correct functioning of the blood vessels, which act as wires that connect our major organs, are essential to the efficiency of this circuit. These vessels divide into thinner branches called arterioles which in turn split into smaller capillaries which surround the cells of the body. The vascular resistance generated by blood vessels is overcome by the blood pressure generated by the heart to enable blood flow. Over time (due to ageing, or a diet high in fat), our blood vessels often harden and become constricted meaning that the heart has to work harder to overcome increased vascular resistance to maintain steady blood flow. The vessels in the limbs are the most peripheral to the heart and thus the most vulnerable to the process of hardening and narrowing over a long period.

The application of water in our daily routine “exercises” these blood vessels by alternately contracting and dilating them. Water can act as an agent of temperature gradients, thereby affecting the thermoregulatory response of the cutaneous circulation. When hot, water ensures that vessels in the limbs dilate, and when cold, that they contract. In this way, water ensures the flexibility of vessels distant from the heart, forcing nutrients deposited in tissues as a result of poor circulation back into the bloodstream through a temperature gradient.

Lymphatic system

The lymphatic system, on the other hand, is probably not the first to come to mind when we think of the body’s organ systems. Yet without this quietly working system our cardiovascular system would collapse and our immune system would be impaired. Our lymphatic vessels transport “leaked” blood fluids into our capillaries to prevent the accumulation of fluid in the interstitial spaces and eventual tissue damage. The vessels of the lymphatic system are much thinner than those of the cardiovascular system, ensuring the circulation of white blood cells which have an essential role in protecting the body against invaders and resisting disease. It is this fluid that we see oozing out when we have a cut or wound.

The optimal functioning of this system and its thin vessels, like those of the circulatory system, can be said to be closely linked with the effect of washing. The phagocytes and lymphocytes, which make up the immune system are housed by our lymphoid tissues and organs, are supported by the act of wudhu. The nasopharyngeal region behind the nose leads to the tonsils, which are small masses of lymphoid tissue that trap and remove pathogens that are entering the throat. Washing the mouth and nose three times with every wudhu therefore helps to remove the bacteria that builds up in the region of the body most exposed to the external environment. Moreover, the act of washing both sides of the neck during wudhu stimulates our cervical lymph nodes – a specialized mass of tissue which houses lymphocytes and particularly helps to protect the body by removing bacteria and tumor cells from lymphatic circulation. Our lymphocytes are arguably the most important component of our immune system, patrolling every point of the body many times a day and destroying cancer cells and pathogens along the way. Considering that the act of wudhu enhances the filtration effect of our lymphoid circulation, one can see the blessings that come with the divine command to “wash…and purify your bodies fully….”

Electrostatic balance

Our physiology is also closely related to the electrostatic balance of the body. While many psychosomatic diseases result from electrostatic imbalance, the most pronounced effect of static electricity is exerted on the subcutaneous muscles located under the skin, mitigating their function and inducing the onset of wrinkles which often start in the face. Maintaining the regular habit of washing the skin – particularly the face which is most frequently exposed to ultraviolet radiation – protects the surface and internal layer of our skin cells by constantly dampening the skin surface with clean water. It is a much simpler alternative to spending hundreds and hundreds of dollars on expensive skin care and makeup products to maintain a healthy complexion.

In regards to how wudhu can benefit our electrostatic balance, the part of the verse which sheds light to tayammum, “if you cannot find water, then take wholesome dust and wipe your faces and hands with that” highlights that the water substitute for wudhu significantly reduces static electricity, like water. This is why when wudhu is performed calmly with care, it often leaves one feeling refreshed and discharged.

The Quran is a grand source containing many prescriptions for good health. While every civilized person may wash their face and hands throughout the day, wudhu ensures that cleanliness and a sense of well-being is sustained by virtue of its association with worship. The worth and significance of wudhu is not limited to the medical benefits discussed here. However, for anyone else wondering why taking a pause on a busy day with wudhu feels so rejuvenating, I hope this humble article sheds some light to a grand prescription from among the many medicines revealed in the Qur’an.

One of the processes that occurs in the body is called “inflammation.” Inflammation occurs when a cut into the skin also punctures a blood vessel. This situation directly exposes the blood to the air. Inflammation occurs in a few steps. First, the blood vessels near the wound are expanded (which causes the swelling that we see near the cut) and special proteins called “fibrins” are brought in. These fibrins bind to each other to form a net-like structure. We are all quite familiar with this net, which we call a blood clot. This net stops the bleeding and cuts the interaction between the air and the blood within a few minutes.

Next, it is time to quickly eliminate any foreign objects that got into the tissue. Special immune cells called “macrophages” are sent to the crime scene to clean up. Macrophages are large white blood cells that “eat” microbes and other foreign objects using a process called “phagocytosis.” After the scene is all cleaned up, these macrophages excrete special molecules that induce tissue repair and return the blood flow to normal. An important note here is the specific order of these events. Like every single process in the body, they occur in the most purposeful way possible. What do I mean? I mean that, first the wound is closed urgently; second, macrophages are sent in; third comes the tissue repair. Any other order would have greatly lowered the effectiveness of inflammation. Imagine that the wound is closed after the macrophages are sent in. Then, by the time the macrophages killed all the microbes, twice as many would have entered the scene. The body seems to know every single event beforehand and plans its defense accordingly.

Our body is perfectly calibrated to keep our blood, the milk of our organ systems, absolutely pristine.

Let’s say a microbe managed to sneak into the blood before inflammation occurred, and is long gone to another region of the body. Does the microbe win? Unfortunately for the microbe, it has to pass another test. This time the tester is the lymphatic system. The lymphatic system is the sewage system of the body. When the blood transfers its nutrients to the tissue, the fluid goes through the “interstitial area” (the empty space between organs). During this process, some of the fluid stays in this area and starts to accumulate. This is where the lymphatic system kicks in. The lymphatic system consists of many tubes running parallel to the blood vessels and recollects any excess fluid and transports them to the subclavian vein near the neck. This way, excess fluids of the body and all of the molecules in them, are reintroduced into the circulation. If there is a problem with this process, an abnormality called “edema” occurs. Of course, the blood is a very sensitive fluid because it travels through the whole body and seeps into almost every single cell. If a microbe were to get into it, it would easily spread and cause disease. So, the lympatics first does a checkup on the body fluid. This checkup occurs at special nodes in the system called lymph nodes found all over the body. Two of the most famous lymph nodes are the spleen and the tonsils. Within these nodes are lymphocytes, special immune cells that “tag” bacteria and other microbes to be later destroyed by macrophages. Thus, the blood is continuously cleaned and kept safe from harmful microbes.

Last but certainly not the least, the final inspection the blood goes through takes place in the kidneys. The aforementioned two checkpoints prevent the entrance of any foreign materials into the blood, and the elimination of any microbes lucky enough to somehow make it through. So, the only task to be completed is the elimination of excess molecules formed in the metabolism. For example, the blood in the veins (the vessels that carry carbon dioxide formed by the respiration of cells) is carried to the lungs where the carbon dioxide is exhaled. But, a much more precise mechanism comes into play in the kidneys. Blood vessels that come from all around the body form a knot-like structure in the kidney called the “glomerulus.” This knot-like shape increases the surface area of filtration. The blood running from the glomerulus is then filtered into the “Bowman capsule,” which surrounds the glomerulus.

But wait! The sanitation system is not satisfied with this first filtration and “thinks” that the filtrate is not ready to be excreted by the urine. So, a more delicate filtration occurs right after the filtrate enters the “proximal tubule.” While passing through this tubule, essential molecules are immediately reabsorbed into the body. The most valuable of all these molecules is glucose, since it is the main source of energy in the body. The proximal tubule reabsorbs around 98 % of all the glucose, while the distal tubule scouts out the rest. After the tubules are done with the filtration, not a single glucose molecule is left in the urine. As a matter of fact, the presence of even a few glucose molecules in the urine leads to a diagnosis of “renal glycosuria.”

After the proximal tubule, the filtrate goes into the “loop of Henle,” where it is dipped into a high-concentration environment. Water travels passively (without the need for energy) from low-concentration to high-concentration areas. In the loop of Henle, the urine is low-concentration, so water runs back into the body. Thus, any excess water in the urine is effectively and economically reabsorbed. The big machine that consists of the glomerulus, the Bowman capsule, the tubules, and the loop of Henle is called a “nephron.” Everything described above occurs in a single nephron. The average number of nephrons in one kidney is around 1,000,000. The human bladder holds around 150 ml of urine on average. So, each nephron is actually responsible for 0.00015 ml of urine production. The kidneys filter over 1,000 liters of blood each day, so our blood is kept just as we want it. Millions of tiny nephrons work in unison to take in huge amounts of blood and they know exactly what to leave and what to keep, 24 hours a day, 7 days a week.

Our blood is our life source. It is the milk of the organs, and our organs would dry up without it. Believe it or not, our organs are quite picky. If they are to receive anything they don’t like, they will start acting up. In order to keep the organs happy, the three mechanisms mentioned above have to work hard and not make a single mistake. These mechanisms are, of course, also made up of cells. These miniscule cells “know” exactly what their clients on the ends of the body like and don’t like, and prepare the blood composition accordingly. Only one word can describe these wondrous mechanisms: Impeccable.

Brian Turk is a medical student from New Jersey. He writes on medicine, health, and biology on a freelance basis.

O believers, when you stand for prayer, wash your faces, and your hands up to the elbows, and wipe your heads, and wash your feet up to the ankles. If you are unclean, bathe and purify your bodies fully. But if you are ill or in the middle of travelling or … you cannot find water, then take wholesome dust and wipe your faces and hands with that. For Allah does not wish to burden you, rather He desires to purify you and to complete His blessing and favour upon you so that, perhaps, you may he grateful.[5:6]

Here is a grand prescription from among the many marvels of the Qur’an. The day will come when even non-Muslims will imitate the Muslim wudu or washing before prayer, a privilege and favour Muslims have enjoyed for more than fourteen hundred years. And they have done so, more or less, unawares, as it is only through the discoveries of biologists in the last twenty years that we have come to understand fully the wonderful effects of wudu. The three principal benefits that human health derives from washing are related to the circulatory system, the immune system, and the electrostatic balance of the body.

a) The circulatory system

The circulatory system is twofold. First, the heart pumps blood out to the tissue cells in every part of the body. Second, it collects back the biologically used blood. If this reverse circulation in particular is disturbed, diastolic blood pressure increases and ageing, even the onset of death, may be precipitated.

The healthful condition and functioning of the blood vessels is essential to this twofold circulatory system. Blood vessels resemble flexible tubing, dividing into thinner branches as the distance from the heart increases. If the thinner tubes in particular become hardened and lose their elasticity, pressure and workload upon the heart are increased. This is known in medical jargon as arteriosclerosis.

Various aspects of our lives cause the blood vessels to harden and become constricted. This problem, considered to be the basis of ageing and bodily deterioration, is now a distinct field of medicine on its own. Improper nutrition and nervous reactions can have a serious effect on the condition of the blood vessels. If sclerotic development is observed in a blood vessel, what practical measure can be taken against it?

The hardening and narrowing of blood vessels does not happen all at once, but over a long period. The vessels furthest from the heart, such as those in the brain, feet and hands, are more vulnerable to the process which begins slowly in these locations and goes on continuously with the passage of time. However, there is an application in our daily routine which, in a sense exercises blood vessels by alternately contracting and dilating them. Its agent is water, which gives rise to temperature gradients. Water ensures flexibility and visor of vessels distant from the heart by dilating them when hot and contracting them when cold. It also forces nutrients, deposited in tissues as a result of sluggish circulation, back into the bloodstream by virtue of the temperature difference.

In view of these facts, is it possible to understand the verse commanding Muslims to wash the hands, feet and face in the wudu rite as anything short of a marvel, particularly in the light of the conclusion of the verse: He desires to…. complete His blessing and favour upon you. Circulation of the blood is a favour to us from the Creator. The command to do wudu completes that favour by maintaining the blood vessels and the circulatory system generally in a healthy state. This is the first of the many blessings of wudu. It is impossible to deny the fact that washing protects against senility which is the way the hardening of blood vessels reflects on the circulation in the brain of a person who has been doing wudu regularly since childhood.

b) The immune system (lymphatic circulation)

In addition to the circulation of red blood cells in the body, there is also the circulation of white blood cells or leucocytes. The vessels of this system are ten times thinner than those which conduct red blood cells. We sometimes see its colourless fluid oozing from the skin walls in some abrasions or wounds. It is this lymphatic circulation which keeps all points of the body within the protection of the immune system. Any bacterium, alien object, or cancer cell (the cause of which is not known), which may have invaded the body is destroyed by the warrior cells or leucocytes in the lymphatic circulation. The appearance of an infectious disease or cancer in the body is always contingent on the malfunctioning of the immune system.

Exactly how this system of vessels expands and contracts has not yet been fully clarified. It is known, however, that heat and cold influence the system. Catching an infectious disease such as a common cold is ascribed to the inability, due to contraction of these vessels, to dispatch leucocytes in sufficient numbers to the afflicted area. Now the proper functioning of this system and its thin vessels, like that of the circulatory system in general, is closely linked with the invigorating effect of washing. The structure of the immune system, which provides resistance against all diseases, is reinforced through the wudu, and the divine favour mentioned in the verse is realized.

Now someone might claim that, while the lymphatic system is indeed invigorated by washing, it is just a coincidental and unintended side effect. However, the precise form of the command to do wudu disposes of this incorrect claim. I would argue, on the contrary, that the way in which the wudu is commanded to be done specifically aims at the lymphatic system as well. The reasons are as follows:

1. For the lymphatic system to function properly, even a single point in the body must not he neglected, which is assured by the full ablution or ghusl.

2. The most important centre for stimulating the lymphatic system is the nasopharyngeal region behind the nose and tonsils, and washing these spots is especially enjoined.

3. Stimulation of both sides of the neck has great influence on the lymphatic system, and this is also present in the wudu.

The most formidable warrior cells of the body, the lymphocytes, are transported to the farthest reaches of the body and, after passing through intensive biological training, patrol each point in the body many times a day. If they meet a bacterium or a cancer cell, they destroy it. Is this not a divine blessing of the first quality? If a circulatory disorder occurs once in a while and you are able to avert or mitigate its effect by means of regular wudu, is it not proper to regard the command as the promised fulfilment of divine favour for which mankind are required to give thanks?

c) Static electricity

The body normally has a balance of static electricity, and the physiology of a healthy body is closely related to this electrostatic balance.

Atmospheric conditions, as well as plastic clothing and products common in our time can adversely affect this balance. Painful illnesses, irritability and facial wrinkles are the best-known results. Most of us have become aware of this electricity when climbing out of a car or after sitting in a plastic chair. Stormy weather has a comparable effect. Healing by acupuncture and, in certain respects, physiotherapy, can redress this imbalance of static electricity; but we can avoid the effect entirely, simply by doing the wudu several times a day.

There are many psychosomatic illnesses arising from electrostatic imbalance. I shall not dwell on these here. I shall address only the question of skin care, which has become such a fashionable subject now.

The worst influence of static electricity is exerted continually on the small subcutaneous muscles (under the skin), finally rendering them inoperative, which is why wrinkles set in, starting with the face, though the skin is affected over the whole body. At this point, many of my readers will have divined at least one of the reasons for the radiant appearance of those who have done wudu all their lives. Whoever maintains the habit of regular washing inevitably has the more healthy, and therefore the more beautiful, skin. How remarkable it is that in our time, when millions are spent on cosmetics, a tenfold increase in expenditure would still not properly substitute for simple washing.

Doubtless, the sceptic will ask, but does wudu really have anything to do with static electricity?

Of course it does. The part of the verse pertaining to tayyamum when water is not available for wudu, underlines the fact. For this substitute for wudu also disposes of static electricity to a significant extent. Indeed, the importance of it has hitherto gone unrecognized, and no-one has tried to explain why, tayyamum can take the place of wudu when the necessity arises.

As the verse clearly states, the sanitary aspect of wudu is a great blessing which we can now partially explain in medical terms. A person might well say: But I already wash my face and hands anyway. Let us recall, however, that as a widespread public habit, this practice has a very short history (barely seventy years or so) even amongst nations who have a tendency to claim to be the most civilized in the world. More important, cleanliness based on a sort of general good advice can never be sustained with the steadiness of discipline which, in Islam, it has by virtue of its association with worship.

To be sure, the worth and significance of wudu does not end with these medical observations the sense of well-being and dignity derived from wudu also contribute to the general health of the practising Muslim but here my aim has been to make widely known precisely those additional medical benefits.