Therefore all hands shall be weakened. He shows that the power of the Lord to destroy the inhabitants of Babylon will be so great, that they shall have no means of withstanding his anger. Though they stood high in wealth and in power, yet their hearts would be so faint, and their hands so weak, that they would have neither disposition nor ability to resist. And thus he indirectly ridicules the cruelty which boiled in the hearts of the Babylonians; for it is in the power of God to soften hearts, and to crush, loosen, or enfeeble hands or arms, so that suddenly all their courage shall fall down, and all their strength shall vanish away. When the heart quakes, what will be the use of fortifications, or armies, or wealth, or bulwarks? What avails a well-stocked workshop without a workman? We see this every day exemplified in those to whom in other respects the Lord had communicated large resources. Hence we see how vain is that confidence which we place in outward resources; for they would be of no use to us, if the Lord should strike our hearts with any alarm.

Therefore shall all hands be faint - This is designed to denote the consternation and alarm of the people. They would be so terrified and alarmed that they would have no courage, no hope, and no power to make resistance. They would abandon their plans of defense, and give themselves up to despair (compare Jeremiah 50:43 : 'The king of Babylon hath heard the report of them, and his hands waxed feeble; anguish took hold of him, and pangs as of a Women in travail;' Ezekiel 7:17; Zephaniah 3:16).
And every man's heart shall melt - Or, shall faint, so that he shall have no courage or strength (compare Deuteronomy 20:8). The fact was, that the destruction of Babylon took place in the night. It came suddenly upon the city, while Belshazzar was at his impious feast; and the alarm was so unexpected and produced such consternation, that no defense was attempted (see Daniel 5:30; compare the notes at Isaiah 45:1).

Therefore shall all hands be faint,.... Or hang down; that is, the hands of all the Babylonians, the city being taken suddenly and at once, so that they should not be able to lift them up to lay hold on a weapon, and defend themselves:
and every man's heart shall melt; like wax before the fire; be dispirited, and lose all their valour and courage, have neither power nor heart to resist their enemies, and attempt to save themselves.

faint . . . melt--So Jeremiah 50:43; compare Joshua 7:5. Babylon was taken by surprise on the night of Belshazzar's impious feast (Daniel 5:30). Hence the sudden fainting and melting of hearts.

Amazed - To see so impregnable a city as Babylon, so easily and unexpectedly taken. Flames - Hebrews. faces of flame, inflamed with rage and torment.