2 Chronicles 13:9-10

Have ye not cast out the priests of the LORD, the sons of Aaron, and the Levites, and have made you priests after the manner of the nations of other lands? so that whosoever cometh to consecrate himself with a young bullock and seven rams, the same may be a priest of them that are no gods. But as for us, the LORD is our God, and we have not forsaken him; and the priests, which minister unto the LORD, are the sons of Aaron, and the Levites wait upon their business