Calf on the Altar

It's an Idiom.

This incident is taken from the Old Testament. When Moses went up to the mountain to meet God the Israelites made a calf of Gold on the altar and started worshiping it. As an idiom calf on the altar is blaspheming God. Don’t be a calf on the altar and read astrology columns. Calf on the altar is a deadly sin. God is jealous about the people performing the calf on the altar.