The fires of Prāṇa remain awake in this city. The Apāna is, verily, the Gārhapatya fire; and the Vyāna is the Anvāhāryapacana fire. And the Prāṇa is the Āhavanīya fire, because it is carried from the Gārhapatya.

The body is the city (purā), and in it “remain awake” (jāgrati) the “fires of Prāṇa” — the three main prāṇas are identified with the three fires of the Vedic sacrifice:

1. Apāna = Gārhapatya — the domestic fire, always burning, located in the west. Apāna operates in the lower part of the body (abdomen, pelvis), as the gārhapatya is the base fire of the home.

2. Vyāna = Anvāhāryapacana — the southern fire (Dakṣiṇāgni), where food is prepared. Vyāna circulates throughout the body, distributing nutrition, as this fire prepares the oblations.

3. Prāṇa = Āhavanīya — the eastern fire, where the main oblations are offered. Prāṇa, carried from apāna (as fire is carried from gārhapatya to āhavanīya), is the main offering of life.

This correspondence between physiology and ritual is characteristic of yoga. The body is the altar, and the prāṇas are the sacred fires.