We have here an account of the regulation of the militia of the kingdom. David was himself a man of war, and had done great things with the sword; he had brought into the field great armies. Now here we are told how he marshalled them when God had given him rest from all his enemies. He did not keep them all together, for that would have been a hardship on them and the country; yet he did not disband and disperse them all, for then he would have left his kingdom naked, and his people would have forgotten the arts of war, wherein they had been instructed. He therefore contrived to keep up a constant force, and yet not a standing army. The model is very prudent. 1. He kept up 24,000 constantly in arms, I suppose in a body, and disciplined, in one part or other of the kingdom, the freeholders carrying their own arms and bearing their own charges while they were up. This was a sufficient strength for the securing of the public peace and safety. Those that are Israelites indeed must learn war; for we have enemies to grapple with, whom we are concerned constantly to stand upon our guard against. 2. He changed them every month; so that the whole number of the militia amounted to 288,000, perhaps about a fifth part of the able men of the kingdom. By being thus distributed into twelve courses, they were all instructed in, and accustomed to, military exercises; and yet none were compelled to be in service, and at expenses, above one month in the year (which they might very well afford), unless upon extraordinary occasions, and then they might all be got together quickly. It is the wisdom of governors, and much their praise, while they provide for the public safety, to contrive how to make it effectual and yet easy, and as little as possible burdensome to the people. 3. Every course had a commander in chief over it. Besides the subaltern officers that were rulers over thousands, and hundreds, and fifties, there was one general officer to each course or legion. All these twelve great commanders are mentioned among David’s worthies and champions, 2 Sam. 23:8-39; 1 Chron. 11:10-47 They had first signalized themselves by their great actions and then they were advanced to those great preferments. It is well with a kingdom when honour thus attends merit. Benaiah is here called a chief priest, 1 Chron. 27:5. But, cohen signifying both a priest and a prince, it might better be translated here a chief ruler, or (as in the margin) a principal officer. Dodai had Mikloth (1 Chron. 27:4) either for his substitute when he was absent or infirm, or for his successor when he was dead. Benaiah had his son under him, 1 Chron. 27:6. Asahel had his son after him (1 Chron. 27:7), and by this it seems that this plan of the militia was laid in the beginning of David’s reign; for Asahel was killed by Abner while David reigned in Hebron. When his wars were over he revived this method, and left the military affairs in this posture, for the peaceable reign of his son Solomon. When we think ourselves most safe, yet, while we are here in the body, we must keep in a readiness for spiritual conflicts. Let not him that girdeth on the harness boast as he that puts it off.