| Barnes' Notes on the Bible 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 23:7-23; 1 Chronicles 24:20-30 is 25.
Clarke's Commentary on the BibleThese 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.
Gill's Exposition of the Entire BibleThese likewise cast lots over against their brethren, the sons of Aaron,.... These, being divided into twenty four classes also, cast lots, which class should answer to, attend upon, and serve the first course of the priests, and which the second, and so on. And this they did in the same solemn and public manner as the priests had done: in the presence of David the king, and Zadok, and Ahimelech, and the chief of the fathers of the priests and Levites; as in 1 Chronicles 24:6. even the principal fathers over against their younger brethren; the sense is, either that the one stood over against the other, to be distributed by lot, the one as well as the other; or they were chosen by lot, let it fall as it would, without any regard to age or dignity, to the seniority or largeness of houses and families; but as they were chosen, be they younger or elder, richer or poorer, their families more or less numerous and ancient, so they took their places.
Keil and Delitzsch Biblical Commentary on the Old Testamentוגו דויד לפני, as in 1 Chronicles 24:6. In the last clause אבות is used for בּית־אבות, as אבות ראשׁי stands frequently for בּית־אבות ראשׁי in these catalogues. הראשׁ stands in apposition to בּית־אבות, the father's-house; the head even as his younger brother, i.e., he who was the head of the father's-house as etc., i.e., the oldest among the brethren as his younger brethren. The Vulgate gives the meaning correctly: tam majores quam minores; omnes sors aequaliter dividebat.
Geneva Study BibleThese likewise cast {f} lots over against their brethren the sons of Aaron in the presence of David the king, and Zadok, and Ahimelech, and the chief of the fathers of the priests and Levites, even the principal fathers over against their younger brethren. (f) That is, every one had that honour which fell to him by lot.
Wesley's Notes 24:31 Over against - Answerable for number and order to those of the priests, so that there should be a course of the Levites for each course of the priests.
Matthew Henry's Concise Commentary24:1-31 The divisions of the priests and Levites. - When every one has, knows, and keeps his place and work, the more there are the better. In the mystical body of Christ, every member has its use, for the good of the whole. Christ is High Priest over the house of God, to whom all believers, being made priests, are to be in subjection. In Christ, no difference is made between bond and free, elder and younger. The younger brethren, if faithful and sincere, shall be no less acceptable to Christ than the fathers. May we all be children of the Lord, fitted to sing his praises for ever in his temple above.
Matthew Henry's Whole Bible CommentaryVerses 20-31 Most of the Levites here named were mentioned before, ch. 23:16, etc. They were of those who were to attend the priests in the service of the house of God. But they are here mentioned again as heads of the twenty-four courses of Levites (and about so many are here named), who were to attend the twenty-four courses of the priests: they are therefore said to cast lots over against their brethren (so they are called, not their lords), the sons of Aaron, who were not to lord it over God's clergy, as the original word is, 1 Pt. 5:3. And, that the whole disposal of the affair might be of the Lord, the principal fathers cast lots over against their younger brethren; that is, those that were of the elder house came upon he level with those of the younger families, and took their place, not by seniority, but as God by the lot directed. Note, In Christ no difference is made between bond and free, elder and younger. The younger brethren, if they be faithful and sincere, shall be no less acceptable to Christ than the principal fathers. | 
