Jesus said to them, "Have you never read in the Scriptures: " 'The stone the builders rejected has become the capstone; the Lord has done this, and it is marvelous in our eyes'? "Therefore I tell you that the kingdom of God will be taken away from you and given to a people who will produce its fruit. He who falls on this stone will be broken to pieces, but he on whom it falls will be crushed." (Matthew 21: 42-43)

Jesus continues his confrontation with the Chief Priests and Elders by drawing on Isaiah's Song of the Vineyard. He quotes directly from Psalm 118.

These are paradoxical sources, especially given the threatening tone of Jesus.

If he had stopped with Isaiah the warning might have been clear. The fifth chapter of Isaiah is full of woeful warnings. "Therefore as the tongue of fire devours stubble, and as dry grass sinks down in the flame, so their root will be as rottenness, and their blossom go up like dust, for they have rejected the law of the Lord of hosts and have despised the word of the Holy One of Israel." (Isaiah 5: 24)

Psalm 118 includes its own woes and worries, "All nation's surrounded me... they surrounded me on every side... They surrounded me like bees, they blazed like a fire of thorns. (Psalm 118: 10-12)

But the Psalm begins with, "O give thanks to the Lord, for he is good; his steadfast love endures forever." It includes, "Hark, glad songs of victory... The Lord has chastened me sorely but he has not given me over to death."

Jesus uses the image of falling. The psalm relates, "I was pushed hard, so that I was falling but the Lord helped me. The Lord is my strength and my song; he has become my salvation."

The Greek that is translated above as "crushed" is likmao. It's most common usage is in the scattering and winnowing involved in separating the good grain from it's chaff.

What we hear and how we understand is often more a reflection of our predispositions than what is actually being said.