Śatapatha Brāhmaṇa ("of a hundred paths") 11.4.4.5

11.4.4.5

atha ya uparaktena haviṣā yajate candramasā ha sa brahmaṇo dvāreṇa pratipadyate sa candramasā brahmaṇo dvāreṇa pratipa

And he who offers with slightly browned sacrificial food, enters through the moon-door of the Brahman, and, by entering through the moon-door of the Brahman, he wins his union with, and participation in the world of, the Brahman.