John Calvin Commentary Zephaniah 2:13

"And he will stretch out his hand against the north, and destroy Assyria, and will make Nineveh a desolation, and dry like the wilderness." — Zephaniah 2:13 (ASV)

The Prophet now addresses the Assyrians, whom we know to have been particular enemies of the Church of God. For the Moabites and the Ammonites were merely instigators, as we have seen elsewhere, since they could not do much harm by their own strength. Therefore, they stirred up the Assyrians; they stirred up the Ethiopians and remote nations.

The meaning, then, is that none of the enemies of the Church would be left unpunished by God, as each one would receive a reward for his cruelty. He speaks now of God in the third person, but in the previous verse God Himself said that the Ethiopians would be slain by His sword. The Prophet adds, He will extend his hand to the north; this means that God will not limit His judgments to the Ethiopians, but He will go further, even to Nineveh and all the Assyrians.

Nineveh, we know, was the capital of the empire before the Assyrians were conquered by the Babylonians. Thus Babylon recovered the sovereignty it had lost. And Nineveh, though not completely demolished, was nevertheless deprived of its ruling power and gradually lost its name and wealth, until it was reduced to a wasteland; for the building of Ctesiphon, as we have seen elsewhere, proved its ruin.

But the Prophet, no doubt, intends here to offer comfort to the Jews, so that they would not despair while the Lord did not yet intervene. The phrase "extension of the hand" signifies, as it were, that the Lord knows His own time and that He would exert His power when necessary. Assyria was north of Judea; therefore, he says, to the north will the Lord extend His hand and will destroy Assyria; He will make Nineveh a desolation, so that it becomes like the desert.