John Calvin Commentary Isaiah 10:26

"And Jehovah of hosts will stir up against him a scourge, as in the slaughter of Midian at the rock of Oreb: and his rod will be over the sea, and he will lift it up after the manner of Egypt." — Isaiah 10:26 (ASV)

And the LORD of hosts will stir up a scourge for him. Here Isaiah makes use of the word scourge, and not rod, meaning that the Lord will treat the enemies much more harshly and severely than they had treated the Jews. He threatens them with extermination, and makes it more evident by two examples: first, that of the Midianites (Judges 7:25), who were cut off by a dreadful slaughter in the valley of Oreb, which was so named from their leader; and, secondly, that of the Egyptians, whom the Lord, when they pursued after his people, sank in the Red Sea (Exodus 14:27, 28). In the former passage, he refers to a narrative which was somewhat more recent, and in the latter to one that was more ancient.

Therefore, we infer that the Lord has displayed his power in defending his Church, so that, when our affairs are in the most desperate state, we may remain steadfast in the faith, and, relying on his grace, we may still cherish a pleasing hope. By means and in ways that are unexpected he often delivers his Church, as he did by the hands of Gideon and Moses. We should always, therefore, remember those benefits, so that we may be stirred more and more to confidence and perseverance.

Therefore, we should also infer that all the afflictions which we endure are the Lord’s rods with which he chastises us; and yet he does not permit Satan or his agents to inflict deadly chastisements upon us. On the other hand, an awful destruction awaits our enemies, as we see in the Midianites and Egyptians. It is, therefore, no small consolation that, when we compare our condition with theirs, we see them, for a time indeed, in all the madness of joy and of wickedness insulting the children of God, but at the same time learn what a dreadful sentence has been pronounced against them; for they are consigned to deadly and everlasting destruction.