2 Samuel 8:3 References

3 Then David defeated aHadadezer, the son of Rehob king of Zobah, as bhe went to restore his rule at the River.

b 2 Samuel 10:15-19

2 Samuel 10

15 When the Arameans saw that they had been defeated by Israel, they gathered themselves together.
16 aAnd Hadadezer sent and brought out the Arameans who were beyond the River, and they came to Helam; and bShobach the commander of the army of Hadadezer led them.
17 Now when it was told David, he gathered all Israel together and crossed the Jordan, and came to Helam. And the Arameans arrayed themselves to meet David and fought against him.
18 But the Arameans fled before Israel, and David killed a700 charioteers of the Arameans and 40,000 horsemen and struck down Shobach the commander of their army, and he died there.
19 When all the kings, servants of Hadadezer, saw that they were defeated by Israel, athey made peace with Israel and served them. So the Arameans feared to help the sons of Ammon anymore.

Other references for 2 Samuel 8:3

a 1 Samuel 14:47, 2 Samuel 10:16, 2 Samuel 10:19