Jamieson, Fausset and Brown on Isaiah 14:31

31. gate--that is, ye who throng the gate; the chief place of concourse in a city.

from ... north--Judea, north and east of Palestine.

smoke--from the signal-fire, whereby a hostile army was called together; the Jews' signal-fire is meant here, the "pillar of cloud and fire," (Ex 13:21; Ne 9:19); or else from the region devastated by fire [Maurer]. Gesenius less probably refers it to the cloud of dust raised by the invading army.

none ... alone ... in ... appointed times--Rather, "There shall not be a straggler among his (the enemy's) levies." The Jewish host shall advance on Palestine in close array; none shall fall back or lag from weariness (Is 5:26, 27), [Lowth]. Maurer thinks the Hebrew will not bear the rendering "levies" or "armies." He translates, "There is not one (of the Philistine watch guards) who will remain alone (exposed to the enemy) at his post," through fright. On "alone," compare Psa 102:7; Ho 8:9.