John Gill Commentary Ezekiel 21:4

"Seeing then that I will cut off from thee the righteous and the wicked, therefore shall my sword go forth out of its sheath against all flesh from the south to the north:" — Ezekiel 21:4 (ASV)

Seeing then that I will cut off from thee the righteous and the
wicked
Some by the sword, some by famine, some by pestilence, and others by captivity; and, upon the whole, none spared, but the land left desolate: therefore shall my sword go forth out of his sheath against all flesh,
from the south to the north ;

the Chaldean army shall go out of their own land against all the inhabitants of Judea, from Beersheba to Dan; this explains what is meant by all faces being burnt from the south to the north, (Ezekiel 20:47) , namely, the general destruction of the Jews by the Chaldeans.