2 Chronicles 23:6-7

6But let no one come into the house of the Lord except the priests and those of the Levites who serve. They may go in, for they are holy; but all the people shall keep the watch of the Lord.

7And the Levites shall surround the king on all sides, every man with his weapons in his hand; and whoever comes into the house, let him be put to death. You are to be with the king when he comes in and when he goes out.”