2 Chronicles 23:2-6

2They traveled throughout Judah and assembled the Levites from all the cities of Judah, as well as the Israelite family leaders. They came to Jerusalem,

3and the whole assembly made a covenant with the king in the temple of God. Jehoiada said to them, “The king’s son will rule, just as the Lord promised David’s descendants.

4This is what you must do. One third of you priests and Levites who are on duty during the Sabbath will guard the doors.

5Another third of you will be stationed at the royal palace and still another third at the Foundation Gate. All the others will stand in the courtyards of the Lord’s temple.

6No one must enter the Lord’s temple except the priests and Levites who are on duty. They may enter because they are ceremonially pure. All the others should carry out their assigned service to the Lord.