Vedic Metre in its Historical Development c17.s2.24

c17.s2.24

(v) The deity of the sacred song is properly Bṛhaspati or Brahmaṇaspati, and in hymns of the two earlier periods this character is strictly preserved. In later hymns the god becomes associated with Indra, and takes the place left vacant by the disappearance of Vāyu, as Indra’s charioteer. As god of song he appears to be replaced in turn by Vāc.