Numbers 8:22
And after that went the Levites in to perform their service in the tabernacle of the congregation before Aaron, and before his sons: as the LORD had commanded Moses concerning the Levites, so did they to them.And after that went the Levites in to perform their service in the tabernacle of the congregation before Aaron, and before his sons: as the LORD had commanded Moses concerning the Levites, so did they to them.