Śatapatha Brāhmaṇa ("of a hundred paths") 4.6.8.5

4.6.8.5

atha yadahareṣāṃ dīkṣā samaiti | araṇiṣvevāgnīntsamārohyopasamāyanti yatra dīkṣiṣyamāṇā bhavanti gṛhapatireva prathamo manthate madhyam prati śālāyā athetareṣāmardhā dakṣiṇata upaviśantyardhā uttarato mathitvopasamādhāyaikaikamevolmukamādāyopasamāyanti gṛhapatergārhapatyaṃ gṛhapatereva gārhapatyāduddhṛtyāhavanīyaṃ dīkṣante teṣāṃ samāna āhavanīyo bhavati nānā gārhapatyā dīkṣopasatsu

But if their consecration falls upon that same day, then, taking up the fires (again) on the churning-sticks, they betake themselves to where they intend to perform the consecration-ceremony. The Grihapati churns (his fire) first somewhere about the centre of the hall; and one half of the others settle down south and one half north of him. Having churned (their fires), and put on fire-wood, they take one fire-brand each and betake themselves together to the Grihapati's Gârhapatya fire. Having taken out the Âhavanîya from the Grihapati's Gârhapatya, they perform the consecration-ceremony. They have one and the same Âhavanîya, but different Gârhapatyas, during the consecration and the Upasads.