1 Chronicles 16:37-40

Then David left Asaph and the other Levites there in front of the Ark of the Agreement with the LORD. They were to serve there every day. David also left Obed-Edom and sixty-eight other Levites to serve with them. Hosah and Obed-Edom son of Jeduthun were guards. David left Zadok the priest and the other priests who served with him in front of the Tent of the LORD at the place of worship in Gibeon. Every morning and evening they offered burnt offerings on the altar of burnt offerings, following the rules written in the Teachings of the LORD, which he had given Israel.