John Gill Commentary Ezekiel 15:5

"Behold, when it was whole, it was meet for no work: how much less, when the fire hath devoured it, and it is burned, shall it yet be meet for any work!" — Ezekiel 15:5 (ASV)

Behold, when it was whole it was fit for no work Before it was cut into pieces, and cast into the fire, it was not fit to make so much as a pin of to hang anything on; so Israel, when all together, before the ten tribes were carried captive, or the Jews before the captivity of Jeconiah, were useless and unfruitful, and to every good work reprobate:

how much less shall it be fit yet for [any] work when the fire has devoured it, and it is burned? As its wood is good for nothing before it is burned, its ashes are useless after.