Śatapatha Brāhmaṇa ("of a hundred paths") 8.2.3.1

8.2.3.1

atha prāṇabhṛta upadadhāti | etadvai devā abruvaṃścetayadhvamiti citimicateti vāva tadabruvaṃste cetayamānā vāyumeva citimapaśyaṃstāmasminnadadhustathaivāsminnayametaddadhāti

He then lays down the Prânabhrit (bricks). For at that time the gods said, 'Meditate ye!' whereby, doubtless, they meant to say, 'Seek ye a layer!' Whilst meditating, they saw even that layer, the wind: they put it into that (fire-altar), and in like manner does he (the priest) now put it therein.