Moses spent 40 days and 40 nights with God on Mount Sinai.
During that time, Aaron made a statue of a false god. The Israelites offered sacrifices to the metal calf and worshipped it. They said the calf was the god who had saved them from slavery in Egypt.
This was a terrible sin because it was a lie about the true God. The Israelites had promised to worship only God. But they were doing the opposite of what they had promised to do.
This made God very sad and angry. He decided to destroy the Israelites. Instead he would make a new nation out of Moses’ family line.
But once again Moses acted as the go-between. He prayed (prayer) for God to have mercy on the people of Israel.
Moses broke the stone tablets that God had given him. This was a picture of how the Israelites had broken their covenant with God. The Israelites suffered for their terrible sin.
Those who were unfaithful to God were killed by Levites who had remained faithful. They were also killed in the plague God sent. This was described as their names being erased from the Book of life