Behold, it is cast into the fire - The wood is in itself useless for any purpose; but what if it have been cast into the fire, and half burned, what of it then?

The fire devoureth both the ends of it, and the midst of it is burned - Judea is like a vine branch thrown into the fire, which seizes on both the ends, and scorches the middle: so both the extremities of the land is wasted; and the middle, Jerusalem, is now threatened with a siege, and by and by will be totally destroyed.

Behold, it is cast into the fire for fuel, That is; a vine tree when cut down, or a branch when cut off, it is good for nothing else; and that is the use it is generally put to; see John 15:6; and this, it is suggested, would be the end of the Jewish nation; who were become by their sins like a wild vine, and were fit fuel for the fire of divine wrath:
the fire devoureth both the ends of it; the branch cast into it, and so is quickly consumed. Kimchi explains this by Isaiah 9:12; "the Syrians before, and the Philistines behind, and they devour Israel with open mouth"; and Abendana of the ten tribes; but it seems only to design how soon the fire takes it; and how inevitable the consumption is when it is fired at both ends:
and the midst of it is burnt: presently; it being dried, and reduced to a brand by the heat of the fire at both ends: this Kimchi interprets of the city of Jerusalem, which was in the midst of the land:
is it meet for any work? no; for if it was not fit for any work when cut down, or cut off, much less when burnt in the fire.

cast into . . . fire-- (John 15:6).
both the ends--the north kingdom having been already overturned by Assyria under Tiglath-pileser; the south being pressed on by Egypt (2-Kings 23:29-35).
midst of it is burned--rather, "is on flame"; namely, Jerusalem, which had now caught the flame by the attack of Nebuchadnezzar.
Is it meet for any work--"it," that is, the scorched part still remaining.

For fuel - When for its barrenness it is cut down, it is fit only to burn.