Śatapatha Brāhmaṇa ("of a hundred paths") 4.4.2.16

4.4.2.16

sajūrdevena tvaṣṭreti | tvaṣṭā vai siktaṃ reto vikaroti tadeṣa evaitatsiktaṃ reto vikaroti somam piba svāhetyuttarārdhe juhoti yā itarā āhutayaste devā athaitāḥ patnya evamiva hi mithunaṃ kLptamuttarato hi strī pumāṃsamupaśeta āharatyadhvaryuragnīdhe bhakṣaṃ sa āhādhvarya upa mā hvayasveti taṃ na pratyupahvayeta ko hi hatasya niraṣṭasya pratyupahavastaṃ vai pratyevopahvayeta juhvatyasyāgnau vaṣaṭkurvanti tasmātpratyevopahvayeta

'Together with the divine Tvashtri'--for Tvashtri transforms the cast seed: thus he thereby transforms the cast seed;--'drink the Soma, Hail!' therewith he offers on the north (left) part (of the fire); what other offerings there are, they are the gods, and these are the wives: thus alone it is a proper union, since the woman lies on the left (north) side of the man. The Adhvaryu takes a draught of Soma to the Agnîdh, and the latter says, 'Adhvaryu, invite me!' [It might be said that] he should not invite him, since how can there be an invitation of one smitten and unmanned? He should nevertheless invite him: they offer in his fire, and utter the Vashat,--therefore he should invite him.