Shatapatha Brahmana 8.3.4.13

8.3.4.13

atha yā dakṣiṇataḥ | yadūrdhvam madhyādavācīnaṃ śīrṣṇastadasya tā atha yāḥ paścādyadūrdhvam pratiṣṭhāyā avācīnam madhyāttadasya tāḥ pratiṣṭhaivottarataḥ

And those which he places on the right (south) side are that (part) of him which is above the waist and below the head. And those at the back are that (part) of him which is above the feet and below the waist. Those on the left (north) side are the feet themselves.