The Upanishads, Part 1 (SBE01), by Max Müller, [1879], at sacred-texts.com
1. While Visvâmitra was going to repeat the hymns of this day (the mahâvrata), Indra sat down near him 4. Visvâmitra (guessing that Indra wanted food) said to him, 'This (the verses of the hymn) is food,' and repeated the thousand Brihatî verses 5
[paragraph continues] By means of this he went to the delightful home of Indra (Svarga).
2. Indra said to him: 'Rishi, thou hast come to my delightful home. Rishi, repeat a second hymn 1.' Visvâmitra (guessing that Indra wanted food) said to him, 'This (the verses of the hymn) is food,' and repeated the thousand Brihatî verses. By means of this he went to the delightful home of Indra (Svarga).
3. Indra said to him: 'Rishi, thou hast come to my delightful home. Rishi, repeat a third hymn.' Visvâmitra (guessing that Indra wanted food) said to him, 'This (the verses of the hymn) is food,' and repeated the thousand Brihatî verses. By means of this he went to the delightful home of Indra (Svarga).
4. Indra said to him: 'Rishi, thou hast come to my delightful home. I grant thee a boon.' Visvâmitra said: 'May I know thee.' Indra said: 'I am Prâna (breath), O Rishi, thou art Prâna, all things are Prâna. For it is Prâna who shines as the sun, and I here pervade all regions under that form. This food of mine (the hymn) is my friend and my support (dakshina). This is the food prepared by Visvâmitra. I am verily he who shines (the sun).'
218:4 Upanishasasâda, instead of upanishasâda. The mistake is probably due to a correction, sa for sha; the commentator, however, considers it as a Vedic license. Skâro 'dhikas khândasah.
218:5 These are meant for the Nishkevalya hymn recited at the noon-libation of the Mahâvrata. That hymn consists of ten parts, corresponding, as we saw, to ten parts of a bird, viz. its body, neck, head, root of wings, right wing, left wing, tail, belly, chest, and thighs. The verses corresponding to these ten parts, beginning with tad id asa bhuvaneshu gyeshtham, are given in the first Âranyaka, and more fully in the fifth Âranyaka by Saunaka. p. 219 Though they consist of many metres, yet, when one counts the syllables, they give a thousand Brihatî verses, each consisting of thirty-six syllables.
219:1 Although the Nishkevalya is but one hymn, consisting of eighty trikas, yet as these eighty trikas were represented as three kinds of food (see Ait. Âr. II, 1, 2, 2-4), the hymn is represented as three hymns, first as eighty Gâyatrî trikas, then as eighty Brihatî trikas, lastly as eighty Ushnih trikas.