Jamieson, Fausset and Brown on 2 Chronicles 24:23

23. at the end of the year the host of Syria came up--This invasion took place under the personal conduct of Hazael, whom Joash, to save the miseries of a siege, prevailed on to withdraw his forces by a large present of gold (2Ki 12:18). Most probably, also, he promised the payment of an annual tribute, on the neglect or refusal of which the Syrians returned the following year, and with a mere handful of men inflicted a total and humiliating defeat on the collected force of the Hebrews.