2 Chronicles 23:3-7

Then all the assembly made a covenant with the king in the house of God. And Jehoiada said to them, “Behold, the king’s son shall reign, as the Lord has spoken concerning the sons of David.

This is the thing which you shall do: a third of you, of the priests and Levites who come in on the Sabbath, shall be gatekeepers,

and a third shall be at the king’s house, and a third at the Gate of the Foundation; and all the people shall be in the courtyards of the house of the Lord.

But no one is to enter the house of the Lord except the priests and the ministering Levites; they may enter, for they are holy. And all the people are to keep the command of the Lord.

The Levites will surround the king, each man with his weapons in his hand; and whoever enters the house is to be put to death. Therefore be with the king when he comes in and when he goes out.”