The system of sacrifices (yajñas and yāgas) forms the link between men and gods. Men propitiate gods through them and gods respond by bestowing upon men what they want. This is the doctrine propounded in the Hindu scriptures like the Bhagavadgītā (3.10-12).
Somayāga is a general name for those sacrifices in which libations of the soma juice are offered in the duly consecrated fire. Agniṣṭoma is a typical Somayāga, forming the prakṛti or model for other Soma sacrifices. It is such an integral part of another well-known sacrifice, Jyoti-ṣṭoma, that these two are often identified. Literally the word ‘Agniṣṭoma’ means ‘praise of Agni’ and the rite derives its name from the hymns called stoma (a group of three ṛks) which are chanted in praise of Agni towards the end of the rite.
On the first day, somapravākas or heralds of Soma sacrifice are sent out to invite priests. Choosing the priests, dīkṣā (initiatory rites) of the sacrificer including another small sacrifice called Dīkṣaṇīyā-iṣṭi and construction of bamboo sheds are the other rites to be performed.
On the third day, pravargya and upasad rites are repeated followed by the construction of mahāvedi and uttaravedi (altars for performing the sacrifices).
On the fourth day, after once again performing pravargya and upasad rites, fire is ceremonially transferred from the old and permanent sacrificial shed to the new. This is known as agnīṣoma-praṇayana. (See AGNĪṢOMA-PRAṆAYANA for details.) An animal sacrifice (paśu-bandha) is also performed.
On the fifth and the last day called ‘sutyā,’ the soma juice is extracted cere-monially three times and offered. The first called prātassavana is done in the morning. The second, mādhyandina-savana is done at noon. At the end of this, sacrificial fees are distributed. Soon after this, begins the third pressing called tṛtīyā. At the end of the sacrifice, all those directly involved in it have avabhṛtha-snāna (ceremonial bath marking the conclusion of the sacrifice).
See also JYOTIṢṬOMA.