The Levites are Rewarded for Their Obedience
As he approached the camp Moses saw the bull-calf and the dancing, and in a burst of anger he flung down the tablets and shattered them at the foot of the mountain. He destroyed the golden calf and said, “Who is on the Lord’s side? Come to me.” The Levites rallied to him, and he said to them, “The Lord commands each of you to arm himself; go through the camp and kill brother, friend and neighbor.” They obeyed, and about three thousand people died that day. Moses said, “You have been made priests of the Lord today, because you each turned against his own son and his own brother, and so have brought a blessing upon yourselves.”
— Exodus 32:19