Exodus 32:27-35

Then Moses said to them, “The LORD, the God of Israel, says this: ‘Every man must put on his sword and go through the camp from one end to the other. Each man must kill his brother, his friend, and his neighbor.’ ” The people from the family of Levi obeyed Moses, and that day about three thousand of the Israelites died. Then Moses said, “Today you have been given for service to the LORD. You were willing to kill your own sons and brothers, and God has blessed you for this.” The next day Moses told the people, “You have done a terrible sin. But now I will go up to the LORD. Maybe I can do something so your sins will be removed.” So Moses went back to the LORD and said, “How terribly these people have sinned! They have made for themselves gods from gold. Now, please forgive them of this sin. If you will not, then erase my name from the book in which you have written the names of your people.” But the LORD told Moses, “I will erase from my book the names of the people who sin against me. So now, go. Lead the people where I have told you, and my angel will lead you. When the time comes to punish, I will punish them for their sin.” So the LORD caused terrible things to happen to the people because of what they did with the calf Aaron had made.