Śatapatha Brāhmaṇa ("of a hundred paths") 7.2.3.3

7.2.3.3

sītāsamare | vāgvai sītāsamaraḥ prāṇā vai sītāstāsāmayaṃ samayo vācī vai prāṇebhyo 'nnaṃ dhīyate madhyato madhyata evāsminnetadannaṃ dadhāti tūṣṇīmaniruktaṃ vai tadyatūṣṇīṃ sarvaṃ vā aniruktaṃ sarveṇaivāsminnetadanne dadhāti

[He places it] at the meeting of the furrows, for the meeting of furrows is speech (the mouth), and the furrows (channels) are the vital airs; and this is their place of meeting; and in the mouth food is put for the vital airs. In the middle (he places the bunch), whereby he puts it into the very middle of him; silently (he does so), for what is silent is undefined, and the undefined is everything: with everything he thus puts food into him.