The Upanishads, Part 1 (SBE01), by Max Müller, [1879], at sacred-texts.com
1. He (the sun), who shines, honoured this world (the body of the worshipper, by entering into it), in the form of man 2 (the worshipper who meditates on breath). For he who shines (the sun) is (the same as) the breath. He honoured this (body of the worshipper) during a hundred years, therefore there are a hundred years in the life of a man. Because he honoured him during a hundred years, therefore there are (the poets of the first Mandala of the Rig-veda, called) the Satarkin, (having honour for a
hundred years.) Therefore people call him who is really Prâna (breath), the Satarkin poets 1.
2. He (breath) placed himself in the midst of all whatsoever exists. Because he placed himself in the midst of all whatsoever exists, therefore there are (the poets of the second to the ninth Mandala of the Rig-veda, called) the Mâdhyamas. Therefore people call him who is really Prâna (breath), the Mâdhyama poets.
3. He as up-breathing is the swallower (gritsa), as down-breathing he is delight (mada). Because as up-breathing he is swallower (gritsa) and as down-breathing delight (mada), therefore there is (the poet of the second Mandala of the Rig-veda, called) Gritsamada. Therefore people call him who is really Prâna (breath), Gritsamada.
4. Of him. (breath) all this whatsoever was a friend. Because of him all (visvam) this whatsoever was a friend (mitram), therefore there is (the poet of the third Mandala of the Rig-veda, called) Visvâmitra. Therefore people call him who is really Prâna (breath), Visvâmitra.
5. The Devas (speech, &c.) said to him (the breath): 'He is to be loved by all of us.' Because the Devas said of him, that he was to be loved (vâma) by all of them, therefore there is (the poet of the fourth Mandala of the Rig-veda, called) Vâmadeva. Therefore people call him who is really Prâna (breath), Vâmadeva.
6. He (breath) guarded all this whatsoever from evil. Because he guarded (atrâyata) all this whatsoever
from evil, therefore there are (the poets of the fifth Mandala of the Rig-veda, called) Atrayah. Therefore people call him who is really Prâna (breath), Atrayah.
214:1 In the first adhyâya various forms of meditating on Uktha, conceived as Prâna (life), have been declared. In the second some other forms of meditation, all extremely fanciful, are added. They are of interest, however, as showing the existence of the hymns of the Rig-veda, divided and arranged as we now possess them, at the time when this Âranyaka was composed.
214:2 The identity of the sun and of breath as living in man has been established before. It is the same power in both, conceived either adhidaivatam (mythological) or adhyâtmam (physiological).
215:1 The real ground for the name is that the poets of the first Mandala composed on an average each about a hundred Rik, verses.