Homa is a Sanskrit word that refers to a ritual, wherein an oblation or any religious offering is made into fire. A Homa is sometimes called a "sacrifice ritual" because the fire destroys the offering, but a Homa is more accurately a "votive ritual". The fire is the agent, and the offerings include those that are material and symbolic such as grains, clarified butter, milk, incense and seeds.
It is rooted in the Vedic religion, and was adopted in ancient times by Buddhism and Jainism. The practice spread from India to Central Asia, East Asia and Southeast Asia. Homa rituals remain an important part of many Hindu ceremonies, and variations of Homa continue to be practiced in current-day Buddhism, particularly in parts of Tibet and Japan. It is also found in modern Jainism.
A Homa ritual is known by alternate names, such as yajna in Hinduism which sometimes means larger public fire rituals, or jajnavidhana or goma in Buddhism. In modern times, a Homa or Havana tends to refer to a private ritual around a symbolic fire, such as those observed at a wedding.
Homa traditions are found all across Asia, from Samarqand to Japan, over a 3000-year history. A homa, in all its Asian variations, is a ceremonial ritual that offers food to fire and is ultimately linked to the traditions contained in the Vedic religion. The tradition reflects a reverence for fire and cooked food (Paka-yajna) that developed in Asia, and the Brahmana layers of the Vedas are the earliest records of this ritual reverence.
Yajna or vedic fire sacrifice ritual, in Indian context, became a distinct feature of the early Sruti (Vedic) rituals. A srauta ritual is a form of quid pro quo where through the fire ritual, a sacrificer offered something to the gods, and the sacrificer expected something in return. The Vedic ritual consisted of sacrificial offerings of something edible or drinkable, such as milk, clarified butter, yoghurt, rice, barley, an animal, or anything of value, offered to the gods with the assistance of fire priests. This Vedic tradition split into Srauta (Sruti-based) and Smarta (Smriti-based).
The Homa ritual practices were copied by different Buddhist and Jaina traditions, states Phyllis Granoff, with their texts appropriating the "ritual eclecticism" of Hindu traditions, albeit with variations that evolved through the medieval times. The homa-style Vedic sacrifice ritual, states Musashi Tachikawa, was absorbed into Mahayana Buddhism and homa rituals continue to be performed in some Buddhist traditions in Tibet, China and Japan.
The Homa ritual grammar is common to many Sanskara (rite of passage) ceremonies in various Hindu traditions. The Vedic fire ritual, at the core of various Homa ritual variations in Hinduism, is a "bilaterally symmetrical" structure of a rite. It often combines fire and water, burnt offerings and soma, fire as masculine, earth and water as feminine, the fire vertical and reaching upwards, while the altar, offerings and liquids being horizontal. The Homa ritual's altar (fire pit) is itself a symmetry, most often a square, a design principle that is also at the heart of temples and mandapas in Indian religions. The sequence of homa ritual events similarly, from beginning to end, are structured around the principles of symmetry. The forms and means of offerings, states Michael Witzel, are symbolism of the masculine and feminine, such as ghee (symbolism of masculine semen) offered into the fire from a ladle ritually shaped in form of a yoni (symbolism for feminine prakriti).
The fire-altar (vedi or homa/havan kunda) is generally made of brick or stone or a copper vessel, and is almost always built specifically for the occasion, being dismantled immediately afterwards. This fire-altar is invariably built in square shape. While very large vedis are occasionally built for major public homas, the usual altar may be as small as 1 x 1 foot square and rarely exceeds 3 x 3 feet square.
A ritual space of homa, the altar is temporary and movable. The first step in a homa ritual is the construction of the ritual enclosure (mandapa), and the last step is its deconstruction. The altar and mandapa is consecrated by a priest, creating a sacred space for the ritual ceremony, with recitation of mantras. With hymns sung, the fire is started, offerings collected. The sacrificer enters, symbolically cleanses himself or herself, with water, joins the homa ritual, gods invited, prayers recited, conch shell blown. The sacrificers pour offerings and libations into the fire, with hymns sung, often to the sounds of svaha. The oblations and offerings typically consist of clarified butter (ghee), milk, curd, sugar, saffron, grains, coconut, perfumed water, incense, seeds, petals and herbs.
The altar and the ritual is a symbolic representation of the Hindu cosmology, a link between reality and the worlds of gods and living beings. The ritual is also a symmetric exchange, a "quid pro quo", where humans offer something to the gods through the medium of fire, and in return expect that the gods will reciprocate with strength and that which they have power to influence.