Śatapatha Brāhmaṇa ("of a hundred paths") 4.2.3.15

4.2.3.15

tadu ha carakādhvaryavo vigṛhṇanti | upayāmagṛhīto 'si devebhyastvā devāvyamukthebhya ukthāvyam mitrāvaruṇābhyāṃ juṣṭaṃ gṛhṇāmyeṣa te yonirmitrāvaruṇābhyāṃ tveti sādayati punarhavirasīti sthālīmabhimṛśati

Now the Karakâdhvaryus divide (the Ukthya libation into three portions), with 'Thou art taken with a support: thee, the god-pleasing, I take for the gods; (thee) the praise-pleasing, for praises, agreeable to Mitra and Varuna!'--with 'This is thy womb: thee to Mitra and Varuna!' he (the Karakâdhvaryu) deposits it; and with 'Thou art a re-offering' he touches the sthâlî.