1 Chronicles 18:3-4 meaning
1 Chronicles 18:3-4 carries David's campaign far to the north, into the Aramean kingdoms of Syria: David also defeated Hadadezer king of Zobah as far as Hamath, as he went to establish his rule to the Euphrates River (v 3). Zobah was an Aramean state north of Damascus, and Hamath lay farther north still, on the Orontes River. Hadadezer carried the name of the storm god Hadad in his own, and he was the strongest ruler in the region, with vassal kings under him (2 Samuel 10:19). Saul had fought the kings of Zobah before David (1 Samuel 14:47), now David completely breaks their power.
The clause, as he went to establish his rule to the Euphrates River (v 3), can be read of either king. The Hebrew is an infinitive with a pronoun suffix, "in his going to set up his hand at the River," and the pronoun has no stated subject. "Hand" can be understood here as authority. The nearest name is Hadadezer, and several translations take him as the one marching to the Euphrates, where he had subjects to call on (1 Chronicles 19:16). David is the subject of the sentence, and the chronicler's verb points his way: 2 Samuel 8:3 says "to restore his rule," which fits a king reasserting what he already held, while Chronicles says establish, which fits a king extending his rule where Israel's rule had yet to reach.
David was marching toward the border God had named to Abraham, "the great river, the river Euphrates" (Genesis 15:18; Joshua 1:4), and Hadadezer stood in his path. Either way the text is read, the outcome is the same: by the end of the chapter David's dominion reaches toward that border, and Solomon will inherit a realm "from the River to the land of the Philistines" (1 Kings 4:21).
The spoils of the victory were enormous: David took from him 1,000 chariots and 7,000 horsemen and 20,000 foot soldiers, and David hamstrung all the chariot horses, but reserved enough of them for 100 chariots (v 4). 2 Samuel 8:4 gives the figures as 1,700 horsemen and 20,000 foot soldiers, with no chariots counted. The Greek translation of 2 Samuel 8:4 reads the numbers as Chronicles does, which suggests that the difference most likely arose in the copying of the Hebrew text of Samuel. Chariots were the heavy weapons of the age, and a king with a thousand of them held the plains.
David's treatment of the horses is the detail the verse dwells on. To hamstring a horse was to cut the tendon of its hind leg, leaving it alive but useless for war. Joshua had done the same to the chariot horses of the northern kings at God's command: "you shall hamstring their horses and burn their chariots with fire" (Joshua 11:6, 9). The law of the king forbade Israel's ruler to "multiply horses for himself" (Deuteronomy 17:16), and the psalmist put the reason plainly: "Some boast in chariots and some in horses, but we will boast in the name of the LORD, our God" (Psalm 20:7).
David kept enough of them for 100 chariots (v 4), a small working force, and destroyed the rest. The king who had just been promised that God would subdue his enemies rested his security on the LORD, and his treatment of the captured horses showed it. Solomon would later gather 1,400 chariots and 12,000 horsemen (1 Kings 10:26) and import horses from Egypt against the letter of the law (1 Kings 10:28-29), and the contrast between father and son on this point is instructive. David's reliance on the LORD, shown in what he did with captured horses, is part of what the chronicler holds up for his readers.