Isaiah 66:15

These verses, like the pillar of cloud and fire, have a dark side towards the enemies of God's kingdom and all that are rebels against his crown, and a bright side towards his faithful loyal subjects. Probably they refer to the Jews in captivity in Babylon, of whom some are said to have been sent thither for their hurt, and with them God here threatens to proceed in his controversy; they hated to be reformed, and therefore should be ruined by the calamity (Jer 24:9); others were sent thither for their good, and they should have the trouble sanctified to them, should in due time get well through it and see many a good day after it. Many of the expressions here used are accommodated to that glorious dispensation; but doubtless the prophecy looks further, to the judgment for which Christ did come once, and will come again, into this world, and to the distinction which his word in both makes between the precious and the vile. I. Christ will appear to the confusion and terror of all those that stand it out against him. Sometimes he will appear in temporal judgments. The Jews that persisted in infidelity were cut off by fire and by his sword. The ruin was very extensive; the Lord then pleaded with all flesh; and, it being his sword with which they are cut off, they are called his slain, sacrificed to his justice, and they shall be many.

— Matthew Henry's Concise Commentary (public domain)

(Isa 9:5; Psa 50:3; Hab 3:5; Th2 1:8; Pe2 3:7). chariots . . . whirlwind-- (Jer 4:13). render--as the Hebrew elsewhere (Job 9:13; Psa 78:38) means to "allay" or "stay wrath." MAURER translates it so here: He stays His anger with nothing but fury," &c.; nothing short of pouring out all His fiery fury will satisfy His wrath. fury--"burning heat" [LOWTH], to which the parallel, "flames of fire," answers.

— Jamieson-Fausset-Brown Commentary (public domain)