John Gill Commentary Luke 20:18

"Every one that falleth on that stone shall be broken to pieces; but on whomsoever it shall fall, it will scatter him as dust." — Luke 20:18 (ASV)

Whosoever shall fall on that stone, shall be
broken ,
&c.] Not who shall fall upon Christ by faith, and build upon him as the foundation stone, for such shall be saved; but that stumble at him, and are offended with him, and fall by unbelief and hardness of heart; such do themselves much hurt and mischief and expose themselves to danger and ruin; they bid very fair for destruction:

but on whomsoever it shall fall ;
as it did with its full weight upon the Jews at their destruction, and as it will upon all Christless sinners at the last day:

it will grind him to powder ;
the ruin of such will be unavoidable, and there will be no recovery; (See Gill on Matthew 21:44).