The eighteenth and nineteenth chapters are the same with #2Sa 8:1-10:19 20:1-26 with very little variations, which are observed in the notes on them, to which the reader is referred. (Gill. See my notes there also.)
David's piety and his prayer we had an account of in the foregoing chapter; here follows immediately that which one might reasonably expect, an account of his prosperity; for those that seek first the kingdom of God and the righteousness thereof, as David did, shall have other things added to them as far as God sees good for them. Here is,
I. His prosperity abroad. He conquered the Philistines (#1Ch 18:1), the Moabites (#1Ch 8:2), the king of Zobah (#1Ch 18:3,4), the Syrians (#1Ch 18:5-8), made the king of Hamath his tributary (#1Ch 18:9-11), and the Edomites, #1Ch 18:12,13.
II. His prosperity at home. His court and kingdom flourished, #1Ch 18:14-17. All this we had an account of before, 2 Samuel 8. (MH)
V. 4, David almost completely obeyed the Lord prohibition against chariots, Deuteronomy 17:16:
But he shall not multiply horses to himself, nor cause the people to return to Egypt, to the end that he should multiply horses: forasmuch as the LORD hath said unto you, Ye shall henceforth return no more that way.
The Lord implies that horses and chariots will cause His king to be lifted up with pride, and be inclined to return to Egypt, maybe with the intent to conquer the nation that held Israel in bondage for so long.
* multiply horses. Multiplying horses for chariots of war and cavalry, or for luxury, would increase the splendour of a monarch, and form a ground of confidence distinct from a proper confidence in God, and inconsistent with it, and with considering him as the glory of Israel. Egypt abounded in horses; and the desire of multiplying these would induce the prince to encourage a trade with that kingdom; and this might make way for the Israelites being again subjugated by the Egyptians, or at least corrupted by their idolatries and vices. Whereas, it was the command of God that they should no more return thither, but be totally detached from them. Besides, they might be tempted to extend their dominion by means of cavalry, and so get scattered among the surrounding idolatrous nations, and thus cease to be that distinct, separate people, which God intended they should be. (TSK, OLB)
What David "dabbled" in, an hundred chariots, his son, Solomon, seems to be controlled by; he kept for himself 1,400 chariots, and 12,000 horsemen.
Vv. 6, 13, the Lord preserved David whithersoever he went. Preservation is of the Lord.
V. 11, David dedicated unto the Lord a tremendous amount of gold and silver. Of course, he had plenty for his own personal use, but he was not stingy with the Lord. At this time in history, the glory of the temple spoke of the glory of God, so the wealth was placed there. Now, however, wealth is to be used to advance the kingdom of God into all the world, Matthew 6:33, 18:19, 20.
V. 14 So David reigned over all Israel, and executed judgment and justice among all his people.
Christ, the Son of David to whom the promises of chapter 17 were given, is right now seated in the place reigning over all principalities, powers, mights, dominions and over every name that is named, not only in this world, but in that which is to come. All things have been placed under His feet, and He is head over all. (Ephesians 1:20-23.) He reigns from that heavenly throne with perfect judgment and justice among all the people of the world.
We give to him of our time and wealth by investing all we have into advancing His kingdom (influence) into all the world through the preaching and teaching of the entire word of God. The Holy Spirit than takes His Word, and He applies it to the hearts, changing individuals by causing them to desire to know and do the will of the Father. As these people learn and apply the word of God into their areas of influence, they claim those areas for the Lord. The heathen are claimed for the kingdom of the Son of David just as sure as the kingdoms in vv. 6-13 were subdued to David's kingdom.
Note v. 6; David places garrisons among the conquered people to prevent their rebellion. Paul established churches (established garrisons) throughout the Roman empire to prevent the return of paganism. We do the same today. Any area conquered by the Gospel of Christ must be retained by establishing garrisons among the pagans. These "garrisons" keep the "locals" controlled.