The Upanishads, Part 1 (SBE01), by Max Müller, , at sacred-texts.com
1. 'Air (vâyu) is indeed the end of all 2. For when fire goes out, it goes into air. When the sun goes down, it goes into air. When the moon goes down, it goes into air.
2. 'When water dries up, it goes into air. Air indeed consumes them all. So much with reference to the Devas.
3. 'Now with reference to the body. Breath (prâna) is indeed the end of all. When a man sleeps, speech goes into breath, so do sight, hearing, and mind. Breath indeed consumes them all.
4. 'These are the two ends, air among the Devas, breath among the senses (prânâh).'
5. Once while Saunaka Kâpeya and Abhipratârin Kâkshaseni were being waited on at their meal, a religious student begged of them. They gave him nothing.
6. He said: 'One god--who is he?--swallowed the four great ones 3, he, the guardian of the world.
[paragraph continues] O Kâpeya, mortals see him not, O Abhipratârin, though he dwells in many places. He to whom this food belongs, to him it has not been given 1.'
7. Saunaka Kâpeya, pondering on that speech, went to the student and said: 'He is the self of the Devas, the creator of all beings, with golden tusks, the eater, not without intelligence. His greatness is said to be great indeed, because, without being eaten, he eats even what is not food 2. Thus do we, O Brahmakârin, meditate on that Being.' Then he said: 'give him food.'
8. They gave him food. Now these five (the eater Vâyu (air), and his food, Agni (fire), Âditya (sun), Kandramas (moon), Ap (water)) and the other five (the eater Prâna (breath), and his food, speech, sight, hearing, mind) make ten, and that is the Krita (the highest 3) cast (representing the ten, the eaters and the food). Therefore in all quarters those ten are food (and) Krita (the highest cast). These are again the Virâg 4 (of ten syllables)
which eats the food. Through this all this becomes seen. He who knows this sees all this and becomes an eater of food, yea, he becomes an eater of food.
58:2 Samvarga, absorption, whence samvargavidyâ, not samsarga. It is explained by samvargana, samgrahana, and samgrasana, in the text itself by adana, eating.
58:3 This must refer to Vâyu and Prâna swallowing the four, as explained in IV, 3, 2, and IV, 3, 3. The commentator explains p. 59 it by Pragâpati, who is sometimes called Ka. In one sense it would be Brahman, as represented by Vâyu and Prâna.
59:1 The food which you have refused to me, you have really refused to Brahman.
59:2 Saunaka wishes the student to understand that though I mortals see him not,' he sees and knows him, viz. the god who, as Vâyu, swallows all the gods, but produces them again, and who, as prâna, swallows during sleep all senses, but produces them again at the time of waking.
59:3 The words are obscure, and the commentator does not throw much light on them. He explains, however, the four casts of the dice, the Krita = 4, the Tretâ = 3, the Dvâpara = 2, the Kali = 1, making together 10, the Krita cast absorbing the other casts, and thus counting ten.
59:4 Virâg, name of a metre of ten syllables, and also a name of food. One expects, 'which is the food and eats the food.'