Śatapatha Brāhmaṇa ("of a hundred paths") 3.2.2.17

3.2.2.17

athāsmai vratam pradāsyannapa upasparśayati | daivīṃ dhiyam manāmahe sumṛḍīkāmabhiṣṭaye varcodhāṃ yajñavāhasaṃ sutīrthā no asadvaśa iti mānuṣāya vā eṣa purāśanāyāvanenikte 'thātra daivyai dhiye tasmādāha daivīṃ dhiyam manāmahe sumṛḍīkāmabhiṣṭaye varcodhāṃ yajñavāhasaṃ sutīrthā no asadvaśa iti sa yāvatkiyacca vrataṃ vratayiṣyannapa upaspṛśedetenaivopaspṛśet

And when he is about to hand the fast-food to him he makes him touch water, with the text, 'For protection we direct our thoughts to divine devotion, the source of supreme mercy, the bestower of glory and the bearer of sacrifices: may it prosper our ways, according to our desire!' Heretofore, indeed, it was for a human meal that he cleansed himself, but now it is for the sake of divine devotion: therefore he says, 'For the sake of assistance we turn our thoughts to divine devotion, the source of supreme mercy, the bestower of glory, the bearer of sacrifices: may it prosper our ways, according to our desire!' Whenever, being about to take the fast-food, he touches water, let him touch it with this same (formula).