These were the orderings of them
Their classes or courses into which they were divided: in their service to come into the house of the Lord;
to perform their service in the temple, according to their turns, and in course as fixed by lot; one class or course served one week, and then went out, and another came in, each consisting of 1000 men, see ( 1 Chronicles 23:4 ) according to their manner;
law, right, custom, here prescribed for them: under Aaron their father; that is, him who was high priest for the time being; who bore this name because his successor and representative, under whose inspection, direction, and authority, all the rest of the priests were, and whom they were to obey in all things: as the Lord God of Israel had commanded him;
to take care they should be done.