And you shall put them on Aaron your brother, and on his sons with him, and shall anoint them and ordain them and consecrate them, that they may serve me as priests. Exodus 28:41.
Then the Lord’s anger burned against Moses and he said, “What about your brother, Aaron the Levite? I know he can speak well. He is already on his way to meet you, and he will be glad to see you.” Exodus 4:14.