The meaning of Yagna is not confined to this sacrificial ritual. It has a much wider and deeper meaning. The word Yagna is derived from the Sanskrit verb yaj, which has a three-fold meaning: worship of deities (deva-pujana), unity (sangatikarana) and charity (daana). The philosophy of Yagna teaches a way of living in the society in harmony and a lifestyle which promotes and protects higher human values in the society, which is indeed the basis of an ideal human culture.
A Vedic (Shrauta) yajna is typically performed by an [Adhvaryu] priest, with a number of additional priests such as the hotar, udgatar playing a major role, next to their dozen helpers, by reciting or singing Vedic verses. Usually, there will be one or three fires in the centre of the offering ground and items are offered into the fire. Among the items offered as oblations (Aahuti) in the Vedic Yajna include large quantities of ghee, milk, grains, cakes, animal meat or Soma. The duration of a yajna depends on the type of yajna; some can last a few minutes, hours, or days, and some even last for years, with priests continuously offering to the gods accompanied with sacred verses. Some Yajnas are performed privately, others with a large number of people in attendance. Post-Vedic Yajnas, where milk products (ghee or yogurt), fruits, flowers, cloth, and money are offered, are called "yaga", homa or havana.
A typical Hindu marriage, too, is a yajna, because the fire deity Agni is supposed to be the witness of all marriages. Brahmins and certain other castes receive a yajnopavita (sacred cord) at their upanayana rite of passage. The yajnopavita symbolizes the right of the individual to study the Vedas and to carry out yagnas or homas.
Temple worship is called agamic, while communication to divinity through the fire god, Agni, is considered Vedic. Today's temple rites are a combination of both Vedic and Agamic rituals. The sacrificial division of Hindu scripture is the Karma-Kanda portion of the Vedas which describe or discuss most sacrifices. The Nambudiri Brahmins of Kerala are among the most famous Shrauta Brahmins who maintain these ancient rituals.
Today, only a few hundred individuals know how to perform these sacrifices and even less are able to maintain the sacred fires continuously and perform the Shrauta rituals. Only a few thousand perform the Agnihotra or basic Aupasana fire sacrifice daily .
This is the basic simple fire sacrifice (in theory) that is to be performed at home twice daily.The Aupasana agni is lit at the time of the groom's wedding from his father's fire . The aupasana can be performed by all four varnas - chaturvarnas . It is also compulsory . However , it is not part of the 21 compulsory fire sacrifices , and is to be performed in addition to those .
The Aupasana Agni lit at the time of the grooms wedding is then divided into two in a sacrifice called Agnyadhana. One part becomes the Grhyagni the other becomes the Srautagni. These two fires are to be preserved throughout the individual's life. The son's fire is lit from the father's fire at the time of his wedding . At the time of the individuals demise , cremation is done with the fires that have been preserved during his lifetime and then the deceased individual's fires are extinguished . The Grhyagni or Aupasanagni is used in the Paka Yajnas; such rituals are described in the Grhyasutras, such as in the Ekagni Kanda of the Apastambha Sutra. Normally this fire is located in the centre or north of the hall which accommodates the sacred fires . This fire may be circular or square .
The rituals pertaining to the three Srautagnis are described in the Shrauta Sutras. Their performers are called Srautin. Fourteen of the 21 compulsory sacrifices are performed in the Srautagnis. They are called Garhapatya, Ahavaniya and Dakshinagni and collectively called the tretagni. The Garhapatya is circular in shape and is situated in the west of the offering ground. Fire is taken from the Garhapatya and kindled in the remaining two fires. The Dakshinagni is semicircular (halfmoon-shaped), is situated in the south and is used for certain rituals, mainly for offerings to the forefathers. The Ahavaniya is square, situated in the east, and is used as the main offering fire of most Srauta sacrifices. The last three Havir Yagnas and all the seven Somayajnas are performed in a specially built Yajnashala.
In the category of nitya-karma there are 21 sacrifices, included in the forty saṃskāras (mostly rites of passage), which are required to be performed at least once in a lifetime of a Dvija. These are divided into groups of seven - paaka-yajnas, havir-yajnas, and soma-yajnas.
Pakayajnas are minor sacrifices and are performed at home in the aupasanagni or grhyagni . These are seven in number .They are Ashtaka , Sthalipaka , Parvana , Sravani , Agrahayani , Chaitri , Ashvayuji. The sthalipaka is to be performed on every Prathama (first day of the lunar fortnight) "Sthali" is the pot in which rice is cooked; it must be placed on the aupasana fire and the rice called "Charu" cooked in it must be offered into the same fire. The Parvana is to be performed every month . The other five are to be performed once a year .
The haviryajnas are more elaborate, though not as large in scale as the somayajnas. The haviryajna performed on every Prathama day (every fifteen days )is "darsa-purna-isti", "darsa" meaning the new moon and "purna" the full moon. The two rituals are also referred to merely as "isti". The Darsapaurnamasa isti is the prakrti (archetype) for the haviryajnas. The first four haviryajnas - adhana, agnihotra, darsa-purna-masa and agrayana - are performed at home. The last three haviryajnas - caturmasya, nirudhapasubandha and sautramani - are performed in a yajnasala.
The Agnihotra is to be performed twice daily at sunrise and sunset immediately after the aupasana .The other five Havir yagnas are to be performed once a year , or at least once in a life time .
The last two havir yagnas have animal sacrifice as part of the ritual . However nowadays packets of flour etc are used as symbolic substitutes .
The name somayajna is called after the juice of the Soma plant, said to be relished by the devas, that is offered as an oblation. In these sacrifices, Samans are sung, and all Shrauta priests - the hotar, adhvaryu, udgatar and the brahman as well as their 12 helpers take part: each priest is assisted by three others. The Agnistoma, the first of the seven somayajnas is the prakrti (archetype) for the six others that are its vikrti. These six are: atyagnistoma, uktya, sodasi, vajapeya, atiratra and aptoryama. Vajapeya is often regarded as particularly important. When its yajamana (sacrificer) comes after the ritual bath (avabhrtha snana) at the conclusion of the sacrifice, the king himself holds up a white umbrella for him. "Vaja" means 'prize of a race' (but is nowadays also taken as rice, food) and "peya" means a drink, thus 'drink of victory'. This sacrifice consists of the offering of soma-rasa (juice), pasu-homa (offering of 23 animals) and anna- or vaja-homa. The sacrificer is "bathed" in the rice that is left over. Since the rice is "poured over" him like water, the term "vajapeya" is apt.
Animal sacrifices are part of the ritual offerings in the soma yagnas . However , nowadays as and when they are rarely performed , substitutes made of flour etc are used instead of sacrificing live animals .
The four Vedas signify the philosophy of the eternity and complementarity of Gayatri and Yagna in the divine creations. The Atharvaveda deals with the sound therapy aspects of Mantras. They can be used for the treatment of the ailing human system at the physical, psychological and spiritual levels. The Samaveda focuses on the musical chanting patterns of Mantras, and the subtle form of Yagna. It defines Yagna as the process of mental oblation on the surface of internal emotions, through the cosmic radiations of the omnipresent subtle energy of sound. The Yajurveda contains the principles and the methods of performing Yagnas as a part of the spiritual and scientific experiments for global welfare.
Experimental studies have shown that Yagna or agnihotra creates a pure, hygienic, nutritional and healing atmosphere. Researchers from the field of microbiology have observed that the medicinal fumes emanating from the process of agnihotra are bacteriostatic in nature, i.e. they eradicate bacteria and micro-organisms, which are the root causes of illness and diseases. The following quotes by renowned scientists are noteworthy:
The following example further illustrates the scientific benefits of Yagna.
Bhopal (Madhya Pradesh, India) Gas Tragedy and Agnihotra The tragic incident occurred on the night of December 3, 1984 when the poisonous MIC gas leaked from Union Carbide factory at Bhopal. Hundreds of people died and thousands were hospitalized, but there were two families – those of Shri Sohan Lal S. Khushwaha and Shri M. L. Rathore, living about one mile away from the plant, who came out unscathed. These families were regularly performing agnihotra (havan). In these families nobody died, nobody was even hospitalized despite being present in the area worst affected by the leakage of the toxic gas. This observation implies that agnihotra is a proven antidote to pollution. (English Daily – “The Hindu” of 4th May 1985; news item under the heading ‘Vedic Way to Beat Pollution’.)