Charles Ellicott Commentary 2 Samuel 8:12

"of Syria, and of Moab, and of the children of Ammon, and of the Philistines, and of Amalek, and of the spoil of Hadadezer, son of Rehob, king of Zobah." — 2 Samuel 8:12 (ASV)

Of Syria. — 1 Chronicles 18:11 reads Edom. As the two names differ in the original by only one very similar letter (the d and r, which are so often confused), it might be supposed that one was an error for the other, if it were not that both nations were actually conquered and the spoils from both were dedicated by David. Syria is mentioned here because Edom has not yet been introduced, and the account of Edom's conquest is given later (2 Samuel 8:14; 1 Kings 11:15–17). Conversely, Edom is mentioned in Chronicles because the spoils from Syria had just previously been specifically mentioned. It may be, however, that both names were originally present in both passages.

Amalek. — This is the only allusion to a war with Amalek after David came to the throne. They had been utterly destroyed by Saul (1 Samuel 15:0); but they were a nation of many tribes, and Saul’s victory can be understood as relating to only one branch. Since David afterwards inflicted a severe blow upon them (1 Samuel 30:0), there is no reason why still other branches of the nation might not have proved troublesome and been defeated by him at other times.