Garudapurana 1.218.30

1.218.30

tataḥ oṃ viśvedevā asminyajñe prīyantā--devabrāhmaṇahaste yavodakadānam /
oṃ prīyantāmiti tenokte oṃ devatābhya iti trirjapet //

Then, offering barley-water into the hand of the brāhmaṇa representing the deities with the formula: "Om, may the Viśvedevas be pleased in this sacrifice." / When he has said, "Om, may they be pleased," one should recite three times: "Om, to the deities..."