'Millstone' in the Bible
“No one shall take a handmill or an upper millstone [used to grind grain into bread] as security [for a debt], for he would be taking a [person’s] life in pledge.
But a certain woman threw an upper millstone [down] on Abimelech’s head and crushed his skull.
Who killed Abimelech the son of Jerubbesheth (Gideon)? Was it not a woman who threw an upper millstone on him from the wall so that he died at Thebez? Why did you go so near the wall?’ Then you shall say, ‘Your servant Uriah the Hittite is also dead.’”
“His heart is as hard as a stone,Indeed, as solid as a lower millstone.
but whoever causes one of these little ones who believe in Me to stumble and sin [by leading him away from My teaching], it would be better for him to have a heavy millstone [as large as one turned by a donkey] hung around his neck and to be drowned in the depth of the sea.
“But whoever causes one of these little ones who believe and trust in Me to stumble [that is, to sin or lose faith], it would be better for him if a heavy millstone [one requiring a donkey’s strength to turn it] were hung around his neck and he were thrown into the sea.
It would be better for him if a millstone [as large as one turned by a donkey] were hung around his neck and he were hurled into the sea, than for him to cause one of these little ones to stumble [in sin and lose faith].
Then a single powerful angel picked up a boulder like a great millstone and flung it into the sea, saying, “With such violence will Babylon the great city be hurled down [by the sudden, spectacular judgment of God], and will never again be found.
And the sound of harpists and musicians and flutists and trumpeters will never again be heard in you, and no skilled artisan of any craft will ever again be found in you, and the sound of the millstone [grinding grain] will never again be heard in you [for commerce will no longer flourish, and normal life will cease].