2 Kings 11:5-7

5And he commanded them saying, This is the thing which ye shall do: a third part of you, that come in on the sabbath, shall be keepers of the watch of the king's house;

6and a third part shall be at the gate of Sur; and a third part at the gate behind the couriers; and ye shall keep the watch of the house for a defence.

7And the two parts of you, all those that go forth on the sabbath, even they shall keep the watch of the house of Jehovah about the king.