In their {x} heat I will make their feasts, and I will make them drunk, that they may rejoice, and sleep a perpetual sleep, and not wake, saith the LORD.

(x) When they are inflamed with surfeiting and drinking, I will feast with them, alluding to Belshazzar's banquet, Da 5:2.

Wesley's Notes

51:39 Heat - When they shall grow hot with wine, I will make them a feast of another nature. Interpreters judge that Belshazzar, Dan 5:1, made a feast to a thousand of his Lords, when he and his wives, and concubines, drank wine in the vessels belonging to the temple, during which feast the city was taken. And not awake - While they were merry with their wine, they fell into a sleep which they never awoke out of.

Jamieson-Fausset-Brown Bible Commentary

39. In their heat I will make their feasts-In the midst of their being heated with wine, I will give them "their" potions,-a very different cup to drink, but one which is their due, the wine cup of My stupefying wrath (Jer 25:15; 49:12; Isa 51:17; La 4:21).

rejoice, and sleep . perpetual, &c.-that they may exult, and in the midst of their jubilant exultation sleep the sleep of death (Jer 51:57; Isa 21:4, 5).

Matthew Henry's Concise Commentary

51:1-58 The particulars of this prophecy are dispersed and interwoven, and the same things left and returned to again. Babylon is abundant in treasures, yet neither her waters nor her wealth shall secure her. Destruction comes when they did not think of it. Wherever we are, in the greatest depths, at the greatest distances, we are to remember the Lord our God; and in the times of the greatest fears and hopes, it is most needful to remember the Lord. The feeling excited by Babylon's fall is the same with the New Testament Babylon, Re 18:9,19. The ruin of all who support idolatry, infidelity, and superstition, is needful for the revival of true godliness; and the threatening prophecies of Scripture yield comfort in this view. The great seat of antichristian tyranny, idolatry, and superstition, the persecutor of true Christians, is as certainly doomed to destruction as ancient Babylon. Then will vast multitudes mourn for sin, and seek the Lord. Then will the lost sheep of the house of Israel be brought back to the fold of the good Shepherd, and stray no more. And the exact fulfilment of these ancient prophecies encourages us to faith in all the promises and prophecies of the sacred Scriptures.