Śatapatha Brāhmaṇa ("of a hundred paths") 1.7.2.16

1.7.2.16

atha triṣṭubhā yajati | tadanayā yajanniyaṃ hi yājyāmuṣyā adhi vaṣaṭkarotyasā u hi triṣṭuptadene sayujau karoti tasmādime sambhuñjāte anayoranu sambhogamimāḥ sarvāḥ prajā anu sambhuñjate

He then presents the offering with a trishtubh verse, thereby presenting it by means of this (earth), for the offering-formula (yâgyâ) is this (earth). Over yonder (sky) he places the vashat, for yonder (sky) also is the trishtubh. Thereby he makes those two (sky and earth) yoke-fellows; and as such they feed together; and after their common meal all these creatures get food.