Vohu Manah, in Pahlavi: Vohuman, or Good Spirit, in the persian mythologyensures the presence of God in the soul of the just, and leads them to Paradise.
His equivalent is the bovine (the bull or cow which provides the urine or milk to be mixed with the homa of the sacrifice). He is lord of fifth creation, the cow or animal.
According to Zoroaster Vohu Manah was the shining Being whom, in his vision, he saw on the river bank that led him to Ahura Mazda. A.G.H.
Sources:
Boyce, Mary, Zoroastrians: Their Religious Beliefs and Practices, New York, Routledge, 2002, p. 19
Grimal, Pierre, Larousse World Mythology, Secaucus, New Jersey, Chartwell Books, 1965, p. 190