John Calvin Commentary Jeremiah 49:14

"I have heard tidings from Jehovah, and an ambassador is sent among the nations, [saying], Gather yourselves together, and come against her, and rise up to the battle." — Jeremiah 49:14 (ASV)

The Prophet again shows that God would be the author of the calamity he speaks of; for if people viewed things, no one could have thought that the Idumeans could be destroyed in such a short time. Therefore, it was necessary for the faithful to raise their minds upward. And this is what the Prophet had in view when he said that all this would be from God.

But his words are especially forceful when he says, We have heard a hearing. Some say, “a report,” but improperly, in my opinion; for though שמועה (shemuoe) often means a report or rumor, here it should be understood as a proclamation, which God published as if by his own heralds. For the analogy is taken from people proclaiming war against their enemies with a solemn ritual. Then Jeremiah says that a voice was heard sent from above, because it was God’s purpose to testify publicly and openly that the destruction of Edom, which we read about here, would take place. So now we understand the meaning of the Prophet when he says, A hearing have we heard from Jehovah.

A confirmation immediately follows: a messenger, or an ambassador, is sent to the nations. Indeed, God had no literal messenger or herald to proclaim war against the Idumeans, or to rouse the Assyrians and Chaldeans. But the Prophets usually spoke in this way, so that people, being led to the very scene, might know that what was said was real and would not be without effect, since prophecies were like so many embassies.

According to this view, the prophets, as we have stated elsewhere, sometimes besieged and stormed cities, or sounded the trumpet, for the very purpose of showing that their doctrine was connected to its execution; for God never spoke through them to no purpose or in vain. The Prophet at the same time reminds us that the Chaldeans and the Assyrians were in God’s hand, so that he could rouse them to war by a nod or a hiss, as it is said elsewhere,

“God will hiss for the fly of Egypt” (Isaiah 7:18).

So the Prophet means that the Chaldeans and the Assyrians would be ready to obey God, as if they were hired soldiers, enlisted under his banner.

So now we see how forceful this way of speaking was; for the faithful could learn from this that it was in God’s power to perform whatever he proclaimed through his servant; for he could by one word rouse, draw, arm, and lead the Assyrians and the Chaldeans to war, as he also says, Be ye assembled, and come against her, and rise up to battle.

And he speaks of many nations so that no one would think that the Idumeans would be able to resist; for an enemy is not necessarily conquered immediately just because they are attacked. But the Prophet addresses this doubt, saying that there would be many nations who would come with their united strength against the people of Edom, so that they would have no power to resist. Nearly the same words are found in Obadiah.