Yajña or sacrifice links the human beings with divine beings. When these divinities or devatās are propitiated through yajñas, they reward the performers with whatever they desire for (vide Bhagavadgītā 3.10-12).
These yajñas may be nitya (obligatory, performed daily), naimittika (occasional) or kāmya (motivated). Again, depending upon the materials used they may be classified as pāka-yajña, havir-yajña and somayāga. If cooked food is offered in pākayajña and soma juice in somayāgas, milk and ghee are the materials normally used in haviryajña.
Agnihotra is one of the most common and important sacrifices which is classed among the haviryajñas and considered to be nitya.
It is performed more as a daily worship than for the fulfilment of any specific desire. It should be started from the very evening of the day on which agnyādhāna (establishing the Vedic fire ceremonially) is done. It is obligatory to perform it daily till death or old-age or saṁnyāsa. All the dvijas (the ‘twice-born,’ the men of the first three varṇas) are entitled to its performance. It must be done twice daily at dawn and dusk, along with the wife. Wife, son or pupil can perform it on his behalf in emergencies.
The main part of the rite consists in heating and offering cow’s milk in a ladle into the gārhapatya fire with appropriate mantras. Sūrya (sun) and Prajāpati are the deities to whom offerings are made in morning and Agni and Prajāpati, in the evening.
Instead of with milk, the rite may be performed with gruel, cooked rice, ghee or curds when specific fruits or results are desired for.
The performer of Agnihotra is obliged to rear a cow. The milk vessel which must be an earthen pot with a straight brim is called ‘agnihotra-sthālī’ and the ladle ‘agnihotrahavaṇī.’
If and when the yajamāna (performer of the sacrifice) goes on a pilgrimage along with his wife, he can carry the gārhapatya fire with him or can ceremonially put it out and perform punarādhāna (re-establishing the fire) on his return.
When he dies, the various wooden implements used by him for Agnihotra should be kept on various parts of his body as prescribed and the body cremated with the gārhapatya fire.