A Prayer to Agni
Here are two verses from the Rigueda invoking Agni, the god of fire: Bring, O strong one, this sacrifice of outs lo the gods. O wise one, as a liberal giver. Bestow on us, O priest, abundant food. Agni, obtain, by sacrificing, mighty wealth for us. Procure, O Agni, for ever to him who prays to you (the gift of) noutishment, the wonderful cow. May a son be ours offspring that continues out line.
Versus such as these were composed in a special kind of Sanskrit, known as Vedic Sanskrit. They were taught orally to men belonging to priestly families.
Why were sacrifices performed during Vedic Petiod?