John Calvin Commentary Jeremiah 48:41

"Kerioth is taken, and the strongholds are seized, and the heart of the mighty men of Moab at that day shall be as the heart of a woman in her pangs." — Jeremiah 48:41 (ASV)

I have already reminded you that the Prophet is not using too many words in this extended discourse, because it was necessary to confirm in detail what everyone would otherwise have rejected. He then says that the cities of Moab were taken, and that strongholds were seized. He mentions these things explicitly because the country of Moab believed it was defended by its cities and strongholds.

They thought, “Should the Chaldeans come and make an invasion, many cities will oppose them; they will then have to spend much time overcoming these obstacles. It might then happen that, exhausted by fatigue, they will return to their own country, and we will recover what we may have lost.” With this confidence, then, the Moabites deceived themselves when they looked at their well-fortified cities and strongholds. For this reason, the Prophet now says, Taken are the cities, and seized on are the strongholds.

There was another thing the Moabites boasted about: that they possessed military valor. Yet they had not recently tested their strength, as they had been indulging themselves in sloth and pleasures. But because they had previously performed deeds worthy of remembrance, they despised their enemies, as I have said, arrogating to themselves the credit of great valor.

The Prophet, on the other hand, declares that their courage would vanish: The heart, he says, of the men of Moab shall become effeminate in that day, softer than the heart of a woman when oppressed by great troubles. It might have seemed a complete comparison when he said that the men of Moab would be soft and effeminate. But he wished to express something more, and so he added that they would become softer than women when in great trouble.

By these words he indicates that it is in God’s power to melt the hearts of men and break down their fierceness, so that those who were like lions are made like does. And this should be carefully noted, because courage is not only a special gift, but it is also necessary that God should daily and constantly strengthen those whom he has once made brave; otherwise, those who are courageous above others will soon lose their valor.