2 Chronicles 23:8

So the Levites and all Judah did according to all things that Jehoiada the priest had commanded, and took every man his men that were to come in on the sabbath, with them that were to go out on the sabbath: for Jehoiada the priest dismissed not the courses.

Jehoiada ... dismissed not the courses. Since it was necessary to have as large a disposable force as he could command on such a crisis, the high priest detained those who, in other circumstances, would have returned home on the expiration of their week of service.