These {g} waited on the king, beside those whom the king put in the fenced cities throughout all Judah.

(g) That is, they were at his ordinary guard.

Wesley's Notes

17:19 Waited - These above - mentioned were the trained bands or auxiliaries: whose chief officers waited on the king to receive his commands, and to raise, and bring in all, or part of their forces, to the service of the king as need required. A vast number for so small a compass of ground, to furnish out and maintain. But we may consider, that God had promised to make the seed of Abraham like the sand of the sea for number; that there had now been a long peace; that many were come to them from the kingdom of Israel and that Jehoshaphat was under a special blessing of God. They were doubtless dispersed all the country over, every one residing on his own land: only they were ready at call, whenever there was occasion.

Matthew Henry's Concise Commentary

17:1-19 Jehoshaphat promotes religion in Judah, His prosperity. - Jehoshaphat found his people generally very ignorant, and therefore endeavoured to have them well taught. The public teaching of the word of God forms, in all ages, the great method of promoting the power of godliness. Thereby the understanding is informed, the conscience is awakened and directed. We have a particular account of Jehoshaphat's prosperity. But it was not his formidable army that restrained the neighbouring nations from attempting any thing against Israel, but the fear of God which fell upon them, when Jehoshaphat reformed his country, and set up a preaching ministry in it. The ordinances of God are more the strength and safety of a kingdom, than soldiers and weapons of war. The Bible requires use to notice the hand of God in every event, yet this is little regarded. But let all employ the talents they have: be faithful, even in that which is little. Set up the worship of God in your houses. The charge of a family is important. Why should you not instruct them as Jehoshaphat did his subjects, in the book of the law of the Lord. But be consistent. Do not recommend one thing, and practise another. Begin with yourselves. Seek to the Lord God of Israel, then call upon children and servants to follow your example.