In the days of Ahaz. The reign of Ahaz covered, probably, the space between B.C. 743 and in B.C. 727. The march on Jerusalem appears to have fallen somewhat late in his reign. Rezin the King of Syria.
Rezin is mentioned as King of Damascus by Tiglath-Pfieser II. in several of his inscriptions. In one, which seems to belong to B.C. 732 or 731, he states that he defeated Rezin and slew him. Pekah the son of Remaliah (see 2 Kings 15:25).
Pekah had been an officer under Pekahiah, the son and successor of Menahem; but had revolted, put Pekahiah to death in his palace, and seized the crown. It is probable that he and Rezin were anxious to form a confederacy for the purpose of resisting the advance of the Assyrian power, and, distrusting Ahaz, desired to place on the throne of Judah a person on whom they could thoroughly depend (see Isaiah 7:6).
It was not their design to conquer the Jewish kingdom, but only to change the sovereign. Toward Jerusalem; rather, to Jerusalem. The allies reached the city and commenced the siege (2 Kings 16:5). Could not prevail against it; literally, prevailed not in fighting against it.