Exodus 32:27-30 New International Reader's Version (NIRV)

27. Then he spoke to them. He said, "The Lord, the God of Israel, says, 'Each man must put on his sword. Then he must go back and forth through the camp from one end to the other. Each man must kill his brother, friend and neighbor.' "

28. The Levites did as Moses commanded. About 3,000 of the people died that day.

29. Then Moses said to the Levites, "You have been set apart for the Lord today. You stood against your own sons and brothers. And he has blessed you this day."

30. The next day Moses said to the people, "You have committed a terrible sin. But now I will go up to the Lord. Maybe if I pray to him, he will forgive your sin."

Exodus 32