Hadadezer appears again in 2 Samuel 10:16 as David's enemy. He may have been the direct son and successor of Rehob. Or he may have been the ruling king from a royal family begun by a king named Rehob. This kingdom was located near the northern city of Dan (see Judges 18:28; compare Numbers 13:21).
Zobah was north and east of David’s kingdom.
who had marched out: The Hebrew text uses a pronoun that simply means “he.” This could refer to Hadadezer, as the Berean Standard Bible translates it. However, some interpreters suggest it could refer to David, meaning that David marched out to strengthen his control over the region.
The Euphrates River: The Hebrew text says only “the river.” First Chronicles 18:3 clearly identifies this river as the Euphrates River. Compare 2 Samuel 10:16.