Shatapatha Brahmana 7.5.2.31

7.5.2.31

bāhyenaivāgnimutsṛjet | ime vai lokā eṣo 'gnirebhyastallokebhyo bahirdhā śucaṃ dadhāti bahirvedīyaṃ vai vedirasyai tadbahirdhā śucaṃ dadhātyudaṅ tiṣṭhannetasyāṃ ha diśyete paśavastadyatraite paśavastadevaiṣvetacucaṃ dadhāti

Let him remove it outside the fire (-altar); that fire (-altar) being these worlds, he thus puts distress outside these worlds;--outside the Vedi; the Vedi being this earth, he thus puts distress outside this earth; (he does so) standing with his face towards the north; for in that region those animals are, and he thus puts distress into them in the region in which they are.