Matthew 21:44

whosoever shall fall on this stone, &c. Lightfoot, Hor. Hebr., sees here a reference to the custom of stoning: "the place of stoning was twice as high as a man. From the top of this, one of the witnesses striking him on his loins, fells him to the ground: if he died of this, well; if not, another witness threw a stone upon his heart."

But it is better to refer the image to an earthenware vessel (1) falling to the ground when it would be shattered, or (2) crushed by a stone when it would be bruised into atoms.

will grind him to powder The Greek word lit. = "to winnow." So "cause to disappear," "destroy." Those to whom Jesus is a "rock of offence" (1 Peter 2:8; Isaiah 8:14) in the days of His humiliation shall have great sorrow: but to incur His wrath when He comes to judge the earth will be utter destruction.