Śatapatha Brāhmaṇa ("of a hundred paths") 8.7.3.18

8.7.3.18

divaspṛṣṭhe vyacasvatīm prathasvatīmiti | divo hyetatpṛṣṭhaṃ vyacasvatprathastaddivaṃ yaca divaṃ dṛṃha divam mā hiṃsīrityātmānaṃ yacātmānaṃ dṛṃhātmānam mā hiṃsīrityetat

'On the back of the sky, thee, the wide and broad one!'--for this (top of the altar) is indeed the back of the sky, and it is both wide and broad;--'Sustain thou the sky! make firm the sky! injure not the sky!'--that is, 'Sustain thy self, make firm thy self, injure not thy self (body)!'