Mah is an ancient Persian god of the moon, one of the Yazatas . He is associated with the cow, which plays an important part in old-Iranian mythology, and presides over time and tide. He is mentioned as an assistant of Vohu Manah . The seventh day of the month is dedicated to Mah.

Mah is also the Persian name of a fish on the back of which the Earth is believed to rest. In popular Islamic mythology, the world sits on a rock, on the back of a bull, on a kamkam (meaning unknown), on the back of a fish, on water, on wind, and on the veil of darkness -- hence the Persian expression az mah ta mahi, 'from the moon to the fish'; i.e., throughout the whole universe.