Shatapatha Brahmana 14.3.1.21

14.3.1.21

uttarato'bhrim taddhi tasyā āyatanaṃ dakṣiṇataḥ samrāḍāsandīṃ taddhi tasyā āyatanamuttarataḥ kṛṣṇājinaṃ taddhi tasyāyatanaṃ sarvato dhavitrāṇi prāṇā vai dhavitrāṇi prāṇānevāsminnetaddad>āti trīṇi bhavanti trayo vai prāṇāḥ pr:ṇa udāno vyānastānevāsminnetaddadhāti

On the left (north) side (he places) the spade, for there is its place of rest; on the right (right) side the imperial throne, for there is its place of rest; on the left side the black antelope-skin, for there is its place of rest; on all sides (save the front side) the fans, for, the fans being the vital airs, he thereby bestows vital airs on it; there are three of them, for there are three vital airs, the out- (and in-) breathing, the up-breathing, and the through-breathing: it is these he thus bestows on him.