John Gill Commentary Isaiah 37:19

"and have cast their gods into the fire: for they were no gods, but the work of men`s hands, wood and stone; therefore they have destroyed them." — Isaiah 37:19 (ASV)

And, have cast their gods into the fire . &c.] And burnt them; and it may well be asked, where are they? (Isaiah 36:19) :

for they were no gods, but the works of men's hands, wood and stone ; they were made of wood or of stone, and therefore could not be called gods; nor could they save the nations that worshipped them, nor themselves, from the fire:

therefore they have destroyed them ; the Assyrian kings were able to do it, and did do it, because they were idols of wood or stone; but it did not therefore follow, that they were a match for the God of Israel, the true, and living God.