John Calvin Commentary Isaiah 29:6

"She shall be visited of Jehovah of hosts with thunder, and with earthquake, and great noise, with whirlwind and tempest, and the flame of a devouring fire." — Isaiah 29:6 (ASV)

From Jehovah of hosts shalt thou be visited. He next assigns the reason why all this multitude of garrisons will be “like chaff;” and he expresses this by an opposite metaphor, for with those soldiers he contrasts the anger and “visitation of the Lord.” What is “chaff” to the flame of “a devouring fire?” What is “dust” to the force and violence of a “whirlwind?” He shows that the vengeance of God will be such that all their preparations will be unable to resist. This meaning, in my opinion, makes the passage flow easily, and the clauses will not be so well adjusted if we follow a different interpretation.

Hence we learn that those who assail us can do no more than what the Lord permits them to do. If therefore the Lord determines to save us, the enemies will accomplish nothing, though they raise up the whole world against us. On the other hand, if he determines to chastise us, we will not be able to ward off his wrath by any force or bulwarks, which will quickly be thrown down as by a “whirlwind,” and will even be consumed as by “a flame.”