Exodus 32:24

Moses said to Aaron, “What did these people do to you, that you have brought a great sin on them?”

Aaron said, “Don’t let the anger of my lord grow hot. You know the people, that they are set on evil.

For they said to me, ‘Make us gods, which shall go before us. As for this Moses, the man who brought us up out of the land of Egypt, we don’t know what has become of him.’

When Moses saw that the people were out of control, (for Aaron had let them lose control, causing derision among their enemies),

then Moses stood in the gate of the camp, and said, “Whoever is on the LORD’s side, come to me!”

All the sons of Levi gathered themselves together to him.

He said to them, “The LORD, the God of Israel, says, ‘Every man put his sword on his thigh, and go back and forth from gate to gate throughout the camp, and every man kill his brother, and every man his companion, and every man his neighbor.’”