Others, of measured food, their food being limited, offer the breaths, the various airs, into the breaths: whichever air is being mastered, they offer the other airs into it, and those airs come to be, as it were, merged in it. All of these are knowers of sacrifice, their stains worn away by sacrifice: their stain worn away, destroyed, by the sacrifices described. Having thus performed the sacrifices described.

This is a brief sub-gloss. For a fuller reading of this verse, see Madhusūdana, Śaṅkara, or Rāmānuja above.

Ramanuja's commentary treats verses 4.29 through 4.30 as a single passage; it is given in full at verse 4.29.

Through drying up the breath by a strictly measured diet, they offer the breaths into the breaths; or else in the manner stated by scriptures such as 'let the wise man hold speech within the mind' (Katha Upanishad 3.13). Something further is established in another text, 'by his slight eating, the breaths are offered into the breaths'.