God planted His vineyard, Israel, and entrusted it to priests, elders, and other leaders for its care. Over many centuries, the Lord sent prophets to check in on these leaders and to receive fruit from the vineyard—that is, a nation mature in righteousness. Israel’s leaders rejected the prophets, and when God decided to send His only Son—Jesus Christ—to them, they killed Him. Therefore, God would destroy those leaders and give charge over His people to others (Luke 20:9–16a). In other words, because the old covenant Jewish leaders were about to reject God’s last offer of repentance to them and kill His Son, God was going to put a new group of leaders in charge of His people: the Apostles, ministers, and elders of the new covenant church.
Plainly, such a rejection of Christ was profoundly foolish, and the parable shows this in two ways. First, the plot of the old covenant leaders to gain the vineyard as an inheritance by killing God’s Son does not make much sense (v. 14). They had no natural right of inheritance, since they were not children of the vineyard owner, so getting rid of the son and heir would not automatically give them title to the vineyard. Their plot was irrational, yet that is what persisting in sin does to people—it makes them lose touch with reason.
Second, the parable of the tenants shows us the foolishness of rejecting Jesus in its depiction of the fate of the tenants, the Jewish leaders. These leaders did not believe that they would lose their position, but Jesus replied by applying Psalm 118 to Himself. Psalm 118 refers to the opposition of the gentile nations to Israel and Israel’s king, promising the faithful that God would save the king and bring these nations to naught. The rejected stone in Psalm 118:22 is the Davidic king, and Jesus declares Himself the rejected stone and fulfillment of the prophecy (Luke 20:17). There is some debate regarding what is meant by the cornerstone in the architecture of the first century. It could be a stone laid at the base of two walls to shore up the foundation or a capstone that helped hold two walls together. Either way, Jesus said that in rejecting Him, the Jewish leaders were rejecting their true King, the man who provided structural integrity to God’s people.
Taking the metaphor further, Jesus says that those who rejected Him, the cornerstone, either would stumble over Him and be broken to pieces or would be crushed by Him (Luke 20:18). All those who impenitently reject Jesus invite their own destruction.