Śatapatha Brāhmaṇa ("of a hundred paths") 11.4.4.3

11.4.4.3

atha yo vipatitena haviṣā yajate vāyunā ha sa brahmaṇo dvāreṇa pratipadyate sa vāyunā brahmaṇo dvāreṇa pratipadya brahmaṇaḥ sāyujyaṃ salokatāṃ jayati

And he who offers with sacrificial food that has fallen (on the ground) enters through the wind-door of the Brahman; and, by entering through the wind-door of the Brahman, he wins his union with, and participation in the world of, the Brahman.