Śatapatha Brāhmaṇa ("of a hundred paths") 4.2.3.5

4.2.3.5

evameva mādhyandine savane | agṛhīta evaitasmādacāvākāyottamo graho bhavatyatha tṛtīyaṃ vasatīvarīṇāmavanayati tatparva samaiti prathamamahottarasya savanasya karotyuttamam pūrvasya sa yaduttarasya tatpūrvaṃ karoti yatpūrvasya taduttamaṃ tadvyatiṣajati tasmādimāni parvāṇi vyatiṣaktānīdamitthamatihānamidamitthaṃ tadyadasyaitenātmā saṃhitastenāsyaiṣa āyuḥ

In like manner at the midday pressing: (when) the last cup has not yet been drawn therefrom for the Akhâvâka priest, he pours (the remaining) one-third of the Vasatîvarî (into the Âdhavanîya). Thus the joint unites; for, indeed, he makes it the first of the second pressing, and the last of the first pressing: that which belongs to the second pressing he makes first, and that which belongs to the first he makes last. Thus he interlocks them; whence these joints are interlocked: this one overlapping thus, and this one thus. And because his body is thereby held together, therefore this (graha) is his vital energy.