Svaha is a propitiatory word used in sacrificial rites in Hinduism. The rites which are offered as oblations through the medium of fire are enjoined in Vedas, Agamas and Grihya Sutras. Svaha is acclaimed to be the glory of Prajapati in Satapatha Brahmana.
The text also ascribes it to the Hemanta (winter) which presides over Prajna (wisdom).
Elsewhere, she is extolled as the vital element of truth, intimately reclining on Brahman’s inherent nature. Svaha belongs to the Latavya kula of rishis. She flashes with radiance of three colors: white, red and yellow.
|Srirangam Ranganathaswamy Temple – Tamil Nadu|
In Nirkuta, svahakara is a term applied to food grains (anna). Svahakara and vastkara are known as the two limbs of speech (vani).
Svaha is the transmitter of the offerings of cooked rice to the gods. The process is common in all kinds of sacrifices (Yajnas and homas) in which svaha is repeated time and again by way of prayer to the gods.
In Brahma Vaivarta Purana, Svaha is the daughter of King Prajapati born of Prasuti. She officiated at the coronation ceremony of the War God, Kartikeya. Devi Bhagavata is full of praise for Svaha and Svadha.
Just as pranava or aum is the primal sound from which creation starts, svaha is a mystic term associated with deva yajna, strongly efficacious in pleasing gods to bestow good fortune and desired object. It consummates a fire offering.
Encyclopedia of Hinduism Volume X page 233 IHRF
Puranic Encyclopedia (1975) – Vettam Mani – Motilal Banarsidass.