The sleeping position of Hindu Tradition is with their heads turned towards the south or towards east, and this immemorial practice finds support in the Puranas Markandeya and Vishnu as well as in the Ahnega Tattwa. When the basic principles underlying the custom is properly understood, the profound knowledge of the sages, who insisted on this principle being followed, stands revealed. The majority of the Hindus believed and still continue to believe that a violation of this principle may result in ill-health. The Puranas and other works, though they hint at such a thing, do not explain the why' of the principle, fearing, perhaps, that doing it will tantamount to instructing the people in the last words of magic or super science very dangerous in the hands of the wicked and the unscrupulous.
Everyone knows that the earth is a huge body magnetized by the force generated by the sun's intense heat. It is also known to all, that the earth is almost round and only one half of it is exposed to the sun's heat at a time. Thus one portion or other of the earth's surface must always remain hot and hence the earth is always being surcharged with the thermal magnetism. The portion not so exposed must, of course, remain lower in temperature than the part so exposed. Perhaps, this combined with diverse other reasons has made the earth retain different kinds of magnetic force at the different poles. The persistence of a magnetic needle in a compass in assuming a position pointing always to the north, however much its equilibrium may be disturbed, fully bears out this truth.
The human body is a magnet, the aggregate red corpuscles which contain a large percentage of iron contributing to it in no small measures. This body has a sphere of influence surrounding and interpenetrating it, just as the earth has of the substance called ether, the medium for such play of forces. It has also two poles, the positive and the negative just as the earth has, in the sphere of ether, otherwise called the sphere of electrons. It is said that objects remain on the surface of the earth because of gravity; but Hindu yogis (sages), who are super scientists, remain suspended in the air against gravity and have an explanation that the change of the polar magnetism in the body by their willpower makes the earth repel them from its surface and hence they easily float in the space.
The sun magnetizes the human sphere of ether as well as the earthly sphere of ether. The earth being a huge sphere and the human sphere being a tiny one, the former influences the latter every second and the influence is the greatest when man lies on the earth, his whole body posture remaining in contact with it, If the influence is to be beneficial, then a man must lie down and sleep with his head turned towards the south or towards the east. When a man lies down and sleeps, the mighty magnet, the earth, at that time of night when man's vitality is at the lowest level, being deprived of the sun's help, pours into or takes away from man his vitality according to the posture he lies in placing his sphere of ether in a position favorable to receive or to give up vitality.
It is an accepted truth that all forces travel in circles and return eventually to the place they stands from. The heart sends out good blood and receives back blood saturated with all sorts of impurities. Similarly, the forces flowing from the North Pole are very pure at first and hence when a portion thereof pours into the human sphere by the position it occupies, it results in the man's good health. The forces returning from the south pole are perhaps saturated with all kinds of impure magnetism. A man by lying down with his head turned towards the south, places himself in a position favorable for the flow of impure magnetism into his body. If a man is naturally strong, the flow of force emanating from his body may counteract this flow of impure magnetism and reduce the evil to a minimum. Else ill-health may be the result. The custom of placing a corpse with the head pointed to the south before its cremation takes place tends to show that the vital magnetism in the body is completely extinct and hence it is only fit to be burnt.
It is also allegorically represented in the story of the elephant headed God, Vinayakar, that one may be deprived of both life and wisdom by sleeping with the head pointing to the north. The story in brief is that Vinayakar had originally a human head. One day he provoked his father Siva to anger and consequently had his head severed from the trunk under His orders. Parvati, Siva's consort, begged Siva to restore to her Vinayakar. Siva there upon directed one of his attendants to go into the forest and bring to him the head of an animal that may happen to be sleeping with the head directed towards the north, meaning thereby that its life is fortified to Yama. An elephant was found to be sleeping with its head turned towards the north. So its head was severed from its trunk and brought to Siva who placed on the trunk of Vinayakar and restored him to life. The elephant represents strength and wisdom and it lost both by sleeping with its head to the north. So the sleeping position with the head directed towards the north one may lose both life and wisdom.