The Syrians that were beyond the river— Beyond the river Euphrates. Hadarezer is the same with Hadadezer, mentioned chap. 2 Samuel 8:3. Houbigant says, that he found it wrote Hadadezer in five manuscripts which he consulted. It is probable that Helam was situated upon the banks of the river Euphrates.
Related Commentaries of 2 Samuel 10:16
2 Samuel 10:16
16 And Hadarezer sent, and brought out the Syrians that were beyond the river:c and they came to Helam; and Shobach the captain of the host of Hadarezer went before them.