Exodus

²⁴And I said unto them, Whosoever hath any gold, let them break it off; so they gave it me: and I cast it into the fire, and there came out this calf. ²⁵And when Moses saw that the people were broken loose; for Aaron had let them loose for a derision among their enemies: ²⁶then Moses stood in the gate of the camp, and said, Whoso is on the Lord'S side, let him come unto me. And all the sons of Levi gathered themselves together unto him. ²⁷And he said unto them, Thus saith the Lord, the God of Israel, Put ye every man his sword upon his thigh, and go to and fro from gate to gate throughout the camp, and slay every man his brother, and every man his companion, and every man his neighbour. ²⁸And the sons of Levi did according to the word of Moses: and there fell of the people that day about three thousand men. ²⁹And Moses said, Consecrate yourselves today to the Lord, yea, every man against his son, and against his brother; that he may bestow upon you a blessing this day. ³⁰And it came to pass on the morrow, that Moses said unto the people, Ye have sinned a great sin: and now I will go up unto the Lord; peradventure I shall make atonement for your sin.