John Calvin Commentary Jeremiah 51:39

"When they are heated, I will make their feast, and I will make them drunken, that they may rejoice, and sleep a perpetual sleep, and not wake, saith Jehovah." — Jeremiah 51:39 (ASV)

Here, he also describes the manner in which Babylon was taken. From this we learn that the Prophet did not speak obscurely or ambiguously, but showed the judgment of God so clearly, as if pointing to it with his finger, so that the prophecy might be known by future generations, enabling them to understand that God’s Spirit had revealed these things through the mouth of the Prophet. For no mortal, even if he had been endowed a hundred times with the spirit of divination, could ever have expressed an unknown thing so clearly.

But since nothing is past or future with God, He thus plainly spoke of Babylon’s destruction through His Prophet, so that future generations, confirmed by the event, might acknowledge with certainty that the Prophet had been the instrument of the Holy Spirit. Daniel later sealed Jeremiah’s prophecy when he historically recounted what had taken place. Indeed, God even extorted a confession from pagan writers, so that they became witnesses to the truth of the prophecy. Although Xenophon was not, in fact, intentionally a witness for Jeremiah, yet that unprincipled writer, whose aim was flattery, nevertheless rendered service to God and, by public testimony, sealed what Jeremiah had divinely predicted.

In their heat, He says, I will make their feasts; that is, I will make them inflamed during their feasts. For when the king of Babylon was drunk, he was slain, together with his princes and counselors. I will make them drunk so that they may exult—that is, so that they may become reckless and unrestrained.

This refers to their drunken folly, for they thought that they would always be safe and ridiculed Cyrus for enduring so many hardships. Cyrus lived in tents, the siege had by then been long, and there was no lack of supplies in the city. Thus, their recklessness destroyed them.

And therefore the Prophet says that God would make them inflamed, so that they might become reckless in their pleasures, and then, that they might sleep a perpetual sleep—that is, that they might perish in their luxury. Although they had despised their enemy, they would never awake. For Babylon, as we observed previously, could have resisted for a long time, but it was taken at once.

Afterwards, the Babylonians were not allowed to have arms. Cyrus, indeed, allowed them to indulge in pleasures, but he took away their weapons and deprived them of all authority, so that they lived in servitude, in the greatest degradation. Then, in the course of time, they became more and more contemptible, until finally the city was so overthrown that nothing remained but a few cottages, and it became an insignificant village. We therefore see that whatever God had predicted through His servant Jeremiah was eventually fulfilled, but at the appropriate time—at the time of treading or threshing, as has been stated.