Notes on the Bible, by Albert Barnes, , at sacred-texts.com
The vine ... - The image is grounded on a well-known figure Psa 80:8; Isa. 5. The comparison is not between the vine and other trees, but between the wood of the vine and the wood of other trees.
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?
They shall go out ... - Rather, they have gone forth from the fire, and the fire shall devour them. The condition of the people is here depicted. The people of Israel - as a whole and as separate kingdoms - had become worthless. The branch torn from the living stem had truly been cast into the fire, which had devoured both ends of it; what remained was a brand plucked from the burning. Those who had escaped the general calamity were reserved for a like fate. Compare Joh 15:6.