Jamieson, Fausset and Brown on 1 Kings 15:18-20

18-20. Then Asa took all the silver and the gold that were left in the ... house of the Lord--Asa's religious character is now seen to decline. He trusted not in the Lord (2Ch 16:7). In this emergency Asa solicited the powerful aid of the king of Damascene-Syria; and to bribe him to break off his alliance with Baasha, he transmitted to him the treasure lying in the temple and palace. The Syrian mercenaries were gained. Instances are to be found, both in the ancient and modern history of the East, of the violation of treaties equally sudden and unscrupulous, through the presentation of some tempting bribe. Ben-hadad poured an army into the northern provinces of Israel, and having captured some cities in Galilee, on the borders of Syria, compelled Baasha to withdraw from Ramah back within his own territories.

Ben-hadad--(See on 1Ki 11:14).