9 Jesus began to tell the people this parable: “A man planted a vineyard and let it out to tenants and went into another country for a long while. 10-12 When the time came, he sent a servant to the tenants, so that they would give him some of the fruit of the vineyard. But the tenants beat him and sent him away empty-handed. And he sent another servant. But they also beat and treated him shamefully, and sent him away empty-handed. And he sent yet a third. This one also they wounded and cast out. 13 Then the owner of the vineyard said, ‘What shall I do? I will send my beloved son; perhaps they will respect him.’” 

14-15 “But when the tenants saw him, they said to themselves, ‘This is the heir. Let us kill him, so that the inheritance may be ours.’ And they threw him out of the vineyard and killed him. What then will the owner of the vineyard do to them? He will come and destroy those tenants and give the vineyard to others.” 16 When they heard this, they said, “Surely not!” 17 But he looked directly at them and said, “What then is this that is written: ‘The stone that the builders rejected has become the cornerstone’? 18 Everyone who falls on that stone will be broken to pieces, and when it falls on anyone, it will crush him.” 19-20 The scribes and the chief priests sought to lay hands on him at that very hour, for they perceived that he had told this parable against them, but they feared the people. So they  watched him and sent spies, who pretended to be sincere, that they might catch him in something he said, so as to deliver him up to the authority and jurisdiction of the governor. Luke 20:9-20 (English Standard Version)

Who was this parable specifically aimed at? (vs 19-20)

It was against those who, in the first part of this chapter, had demanded to know of Jesus who gave Him the authority to do the things He said and did. One of those things was that He had chased out of the temple people who'd turned it into a den of thieves and robbers! The parable is quite straight forward. The servants who were beaten and shamefully treated (vs 9-12) surely referred to the prophets God sent over the centuries urging the nation to bring forth the fruit of righteousness He desired. The 'beloved son' in the story (vs 13) was surely Jesus Himself. It ends with the wrath of the owner of the vineyard falling upon the wicked tenants. (vs 14-15) What was the reply of the Scribes and Pharisees to this conclusion? (vs 16)

I wonder if they suspected that the 'other tenants' to whom the vineyard would be given meant 'to another nation'. In other words, to gentiles! That would've horrified them. Whatever it was that made them react, Jesus then quoted Psalm 118:22 to show that the Scriptures had foreseen and spoken of the situation they were now in. (vs 17) What do you think the message of vs 18 was?

Some suggest that the 'falling and being broken' refers to people who are convicted of sin when they hear about Jesus, and who repent and are saved. That may be. I personally think the ‘falling over’ the cornerstone, or ‘being crushed’ by it, are both part of what happens when people reject the Messiah God has sent into the world. That's how the apostle Peter applied it when he and John were interrogated by the Jewish leaders for preaching about Jesus and the resurrection. Peter said to them: “This Jesus is the stone that was rejected by you, the builders, which has become the cornerstone. And there is salvation in no one else, for there is no other name under heaven given among men by which we must be saved.” (Acts 4:11-12)

Years later, Peter wrote in a letter of what happens to people who realize that Jesus Christ IS the cornerstone on which God builds up a people to be His own. He wrote: “As you come to Jesus, a living stone - rejected by men, but, in the sight of God, chosen and precious - you yourselves like living stones are being built up as a spiritual house, to be a holy priesthood, to offer spiritual sacrifices acceptable to God through Jesus Christ. For it stands in Scripture: 'Behold, I am laying in Zion a stone, a cornerstone chosen and precious, and whoever believes in him will not be put to shame.'” (1 Peter 2:4-6) Through Jesus Christ people are either broken, or built - lost or saved.