Because I will cut off from you both righteous and wicked, therefore my sword shall be drawn from its sheath against all flesh from south to north.
The prophet had faithfully delivered the message he was entrusted with, in the close of the foregoing chapter, in the terms wherein he received it, not daring to add his own comment upon it; but, when he complained that the people found fault with him for speaking parables, the word of the Lord came to him again, and gave him a key to that figurative...
Commenting on Ezekiel 21:1-7
That all flesh may know that I the Lord have drawn forth my sword out of his sheath,.... The same with kindling a fire in Judea; see Gill on Eze 20:48, it shall not return any more; that is, into its sheath, until it has done all its work; meaning that the Chaldean army should not return to their own land until they had executed...
The "sword" did not, literally, slay all; but the judgments of God by the foe swept through the land "from the south to the north."