John Gill Commentary Isaiah 66:15

"For, behold, Jehovah will come with fire, and his chariots shall be like the whirlwind; to render his anger with fierceness, and his rebuke with flames of fire." — Isaiah 66:15 (ASV)

For, behold, the Lord will come with fire Either with material fire, with which mystical Babylon or Rome shall be burnt, (Revelation 18:8) , or with indignation and wrath, which shall be poured out like fire, and be as intolerable and consuming as that:

and with his chariots like a whirlwind ; making a great noise, and striking great terror; alluding to chariots in which men used formerly to fight:

to render his anger with fury, and his rebuke with flames of fire ; a heap of words, to show the fierceness of his wrath, and how severe his rebuke of enemies will be; which will be not a rebuke in love, as of his own people, but in a way of vindictive wrath.