By Swami Harshananda
The homa rites performed as a part of gṛhya or domestic religious ceremonies must always be performed on a sthaṇḍila. A sthaṇḍila is a raised and perfectly leveled altar or platform of sand or loose earth raised by two or four finger breadths. It is a square measuring one iṣu on all the sides. The measurement may be 21 or even 32 aṅgulas. Lines, one horizontal and five vertical, are drawn as prescribed, on which the fire is placed. The sacrificer sits facing the east, whereas the Brahmā priest, the only priest in such rites which sits facing north.
- Iṣu means length of an arrow which is 18 aṅgulas.
- The Concise Encyclopedia of Hinduism, Swami Harshananda, Ram Krishna Math, Bangalore