2 Chronicles 23:4-6

4This is what you shall do: a third of you, of the priests and Levites who are resuming service on the Sabbath, shall be gatekeepers,

5a [second] third shall be at the king’s house (palace), and a [final] third at the Gate of the Foundation; and all the people shall be in the courtyards of the house of the Lord.

6But let no one enter the house (temple) of the Lord except the priests and the Levites who minister; they may enter, for they are holy. And let all the people carefully observe the law of the Lord.