And their brethren in their villages had to come to them from time to time for seven days.

This is what you shall do: One-third of you entering on the Sabbath, of the priests and the Levites, shall be gatekeepers of the doors;

So the Levites and all Judah did according to all that Jehoiada the priest commanded. And each man took his men who were to come in on the Sabbath, with those who were going out on the Sabbath; for Jehoiada the priest had not dismissed the divisions.

Let all things be done decently and in order.

These are the divisions of the sons of Aaron. The sons of Aaron: Nadab, Abihu, Eleazar, and Ithamar.

Therefore, if perfection were through the Levitical priesthood (for under it the people received the Law), what further need was there that another priest should rise according to the order of Melchizedek, and not be called according to the order of Aaron?