1 Chronicles 24:31

Over against their brethren the sons of Aaron, i.e. answerable for number and order to those of the priests, so as there should be a several course of the Levites for each course of the priests. This is expressed concerning the singers, 1Ch 25, and the like is implied concerning the porters, 1Ch 26, and is here sufficiently intimated concerning those Levites which were employed in other sacred ministrations. The principal fathers over against their younger brethren; the lots of the elder and younger brethren were promiscuously put together, and the order was settled as the lots came forth, without any regard to the age, or dignity, or number of the persons or families, the youngest family having thee first course if they had the first lot, &c.