John Gill Commentary 2 Kings 16:5

"Then Rezin king of Syria and Pekah son of Remaliah king of Israel came up to Jerusalem to war: and they besieged Ahaz, but could not overcome him." — 2 Kings 16:5 (ASV)

Then Rezin king of Syria, and Pekah son of Remaliah king of Israel, came up to Jerusalem to war To fight with Ahaz, moved to it by the Lord, to chastise Ahaz for his idolatry, (2 Kings 15:37) (2 Chronicles 28:5).

but could not overcome him so as to take Jerusalem, and set up another king there, as their scheme was, (Isaiah 7:5) though they had both at other times got great advantages over him, and slew many of his people, and carried them captive, see (2 Chronicles 28:5–8).