501. And not the Soul, as the commentator explains. With the death of the body joy and grief disappear.
502. The art by which the body could, as in Egypt, be preserved for thousands of years was not known to the Rishis.
503. The commentator explains the sense of this as follows: The cow belongs to him who drinks her milk. Those who derive no advantage from her have no need for showing her any affection. One should not covet what is above one's want. It has been said, that (to a thirsty or hungry or toil-worn man), a little quantity of vaccine milk is of more use than a hundred kine; a small measure of rice more useful than a hundred barns filled with grain; half a little bed is of more use than a large mansion.
504. I follow Nilakantha in rendering this verse. His interpretation is plausible. Mudatamah, according to him, are those who are in deep sleep. There are four stages of consciousness. These are (1) wakefulness, (2) dream, (3) dreamless or deep slumber, and (4) Turiya or absolute Samadhi (which the Yogin only can attain to).
505. The two extremes, of course, are dreamless slumber and Turiya or Samadhi. The two intermediate ones are wakefulness and sleep with dream.
506. Pride in consequences of having insulted or humiliated others; and success over others such as victories in battle and other concerns of the world.
507. The first half of the second line is read variously. The sense, however, in effect, remains unaltered. What is said here is that man who succeeds in attaining to a state of Brahma by true Samadhi or abstraction from the world, can never be touched by grief.
508. In all treatises on Yoga it is said that when the first stage is passed, the neophyte succeeds in looking at his own self. The meaning seems to be that he experiences a sort of double existence so that he succeeds in himself looking at his own self.
509. This is the same as 46. The Bombay edition does not repeat it.
510. The house referred to is the body. The single column on which it is supported is the backbone, and the nine doors are the eyes, the ears, the nostrils, etc. etc.