Shatapatha Brahmana 1.4.5.13

1.4.5.13

taddhaitaddevāḥ | retaścarmanvā yasminvā babhrustaddha smapṛcantyatreva tyāditi tato triḥ sambabhūva tasmādapyātreyyā yoṣitainasvyetasyai hi yoṣāyai vāco devatāyā ete sambhūtāḥ

That germ (retas) the gods then brought away in a skin or in some (vessel). They asked: 'Is it here (atra)?' and therefore it developed into Atri. For the same reason one becomes guilty by (intercourse) with a woman who has just miscarried (âtreyî); for it is from that woman, from the goddess Speech, that these (germs) originate.