John Calvin Commentary Jeremiah 48:14-15

"How say ye, We are mighty men, and valiant men for the war? Moab is laid waste, and they are gone up into his cities, and his chosen young men are gone down to the slaughter, saith the King, whose name is Jehovah of hosts." — Jeremiah 48:14-15 (ASV)

The Prophet here rebukes the pride of the Moabites because they trusted in their own strength and mocked God and what the Prophets announced. We indeed know that ungodly men, when all things prosper with them, are moved by no fear, rid themselves of all feeling, and become so immersed in indifference that they not only disdainfully disregard the true God but also moral obligations. Such, then, was the confidence that prevailed among the Moabites. Therefore, the Prophet here curbs this foolish boasting.

How say you, We are strong, we are warlike men? It is as though he had said, “These boastings, while God is seriously contending with you, are all empty and will be of no use to you: you think yourselves beyond the reach of danger because you possess great power and are surrounded with strong defenses; but God will reduce to nothing whatever you regard as your protection.” Wasted, then, is Moab. He presents this threat in opposition to their arrogance.

He indeed foretells what was to come but speaks of it as a thing already fulfilled. Wasted, he says, is Moab, and the enemy has cut off his cities. The verb עלה, ole, is to be taken in a transitive sense. It is indeed a neuter verb, but the other meaning is more suitable to this passage: that the enemy would cut off the cities of the Moabites.

I still allow that it may be explained otherwise: that the inhabitants would ascend or depart from his cities. For עלה, ole, metaphorically, indeed, signifies to ascend, and to flow off, or to go away—as they say, in smoke. And if an anomaly in number, common in Hebrew, is accepted, the sense will be, “and from his cities they have vanished.” This explanation agrees well with what follows: and his young men have descended to the slaughter. That is, those who seem the strongest among them shall be drawn to destruction or shall descend to the slaughter.

But as the event seemed difficult to believe, God is again introduced. Then the Prophet says that he did not speak from his own mind but announced what God had entrusted to him. And he adds His title, so that the Jews might be more attentive to the consideration of God’s power.

God, he says, is He who speaks, the King, whose name is Jehovah of hosts. He presents God’s name in opposition to the warlike preparations of which the Moabites, as we have seen, boasted. It is as though he had said that if the Moabites had to deal with mortals, they might indeed have justly gloried; but since they had a contest with the living God, all their power would vanish, as God was prepared to execute vengeance.