Śatapatha Brāhmaṇa ("of a hundred paths") 2.3.3.14

2.3.3.14

uttarato vā agnihotrasya dvāram | sa yathā dvārā prapadyetaivaṃ tadatha yo dakṣiṇata etyāste yathā bahirdhā caredevaṃ tat

On the north side is the door of the Agnihotra: thus (he approaches it) as he would enter (a house) by a door. If, on the other hand, he were to sit down after approaching from the south, it would be as if he walked outside.