Shatapatha Brahmana 4.6.8.6

4.6.8.6

atha yadahareṣāṃ krayo bhavati | tadahargārhapatyāṃ citimupadadhātyathetarebhya upavasathe dhiṣṇyānvaisarjinānāṃ kāle prācyaḥ patnya upasamāyanti prajahatyetānaparānagnīnhuta eva vaisarjine

Then, on whatever day their purchase (of Soma-plants) takes place, on that day he raises the Gârhapatya hearth; and on the Upavasatha day the dhishnya hearths for the others. At the time of the Vaisargina offerings, the wives come forward together and they (the sacrificers) abandon those other (Gârhapatya) fires. As soon as the Vaisargina offering has been performed,--