After the Arameans saw that they had been routed by Israel, they regrouped.
Hadadezer had Arameans brought from beyond the River; they went to Helam, with Shobach the commander of Hadadezer's army leading them.
References for 2 Samuel 10:16
When David was told of this, he gathered all Israel, crossed the Jordan and went to Helam. The Arameans formed their battle lines to meet David and fought against him.
But they fled before Israel, and David killed seven hundred of their charioteers and forty thousand of their foot soldiers. He also struck down Shobach the commander of their army, and he died there.
References for 2 Samuel 10:18
When all the kings who were vassals of Hadadezer saw that they had been defeated by Israel, they made peace with the Israelites and became subject1 to them. So the Arameans2 were afraid to help the Ammonites anymore.
References for 2 Samuel 10:19