Exodus 32:31

27 He told them, “This is what the LORD, the God of Israel, says: ‘Each of you men is to fasten his sword to his side, go back and forth through the camp from gate to gate, and slay his brother, his friend, and his neighbor.’”

28 The Levites did as Moses commanded, and that day about three thousand of the people fell dead.

29 Afterward, Moses said, “Today you have been ordained for service to the LORD, since each man went against his son and his brother; so the LORD has bestowed a blessing on you this day.”

30 The next day Moses said to the people, “You have committed a great sin. Now I will go up to the LORD; perhaps I can make atonement for your sin.”

31 So Moses returned to the LORD and said, “Oh, what a great sin these people have committed! They have made gods of gold for themselves.

32 Yet now, if You would only forgive their sin.... But if not, please blot me out of the book that You have written.”

33 The LORD replied to Moses, “Whoever has sinned against Me, I will blot out of My book.

34 Now go, lead the people to the place I described. Behold, My angel shall go before you. But on the day I settle accounts, I will punish them for their sin.”

35 And the LORD sent a plague on the people because of what they had done with the calf that Aaron had made.

Read all of Exodus 32