Exodus 32:27-28

27And he said to them, “Thus says the  Lord God of Israel, ‘Put your sword on your side each of you, and go to and fro from gate to gate throughout the camp, and each of you a  kill his brother and his companion and his neighbor.’” 28And the sons of Levi did according to the word of Moses. And that day about three thousand men of the people fell.
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