Khadiragrihyasutra 4.3.10

4.3.10

aṣṭarātropoṣitaḥ prāṅvodaṅvā grāmāccatuṣpathe samiddhyāgnimaudumbara idhmaḥ syāt sruvacamasau ca juhuyādannaṃ vā iti śrīrvā iti / 10

He should fast through a period of eight nights, and then should kindle a fire to the east or to the north of the village, at a place where four roads meet. The fuel should be Udumbara wood, and the Sruva and the cup (for water should be of the same wood). Let him sacrifice (Âgya) with (the formulas), 'Food indeed,' and 'Bliss indeed' (MB. II, 6, 13, 14).