These likewise cast lots - The Levites were divided into twenty-four orders; and these were appointed by lot to serve under the twenty-four orders of the priests: the first order of Levities under the first order of priests, and so on. The meaning is not very clear: "both elder and younger," says Bishop Patrick, "had their places by lot, not by seniority of houses. They who were of greater dignity drew lots against those who were of less; and were to take their courses according to the lot they drew." This may have been the case; but we are very little interested in the subject.
The principal fathers over against their younger brethren - i. e., “all the Levitical houses enumerated drew lots in their courses on equal terms, the older families having no advantage over the younger ones.” As there were 24 courses of the priests, so we must suppose that there were 24 of the Levites, though the number of the families as given in the text 1 Chronicles 24:20-30 is 25.