Zephaniah 2:12

The Prophet extends farther the threatened vengeance, and says, that God would also render to the Ethiopians the reward which they deserved; for they had also harassed the chosen people. But if God punished that nation, how could Ammon and Moab hope to escape? For how could God spare so great a cruelty, since he would visit with punishment the remotest nations? For the hatred of the Moabites and of the Ammonites, as we have said, was less excusable, because they were related to the children of Abraham. They ought, on this account, to have mitigated their fierceness: besides, vicinity ought to have rendered them more humane. But as they exceeded other nations in cruelty, a heavier punishment awaited them. Now this comparison was intended for this end—that the Jews might know that God would be inexorable towards the Moabites, by whom they had been so unjustly harassed, since even the Ethiopians would be punished, who yet were more excusable on account of their distance.

As to the words, some regard the demonstrative pronoun המה, eme, they, as referring to the Babylonians, and others, to the Moabites. I prefer to understand it of the Moabites, if we read, like them, or with them, as these interpreters consider it: for they regard the particle את, at, with, or כ, caph, like, to be understood, Ye Ethiopians shall be slain by my sword like them, or with them. It would in this case doubtless apply to the Moabites. But it seems to me that the sentence is irregular, even ye Ethiopians, and then, they shall be slain by any sword. The Prophet begins the verse in the second person, summoning the Ethiopians to appear before God’s tribunal; he afterwards adds in the third person, they shall be slain by my sword. (103)

God calls whatever evils were impending over the Ethiopians his sword; for though they were destroyed by the Chaldeans yet it was done under the guidance of God himself. The Chaldeans made war under his authority, as the Assyrians did, who had been previously employed by him to execute his vengeance. It follows—

Also ye Cushites,
The slain of my sword shall ye yourselves be.

But what Calvin says is not uncommon in the Prophet, the abrupt change of persons.—Ed.