Jesus asked the leaders to weigh a story before they knew it was about them. Barnes calls "what think ye?" "a way of speaking designed to direct them particularly to what he was saying, that they might be self-convicted." Matthew Henry notes that "parables which give reproof, speak plainly to the offenders, and judge them out of their own mouths." Gill says the parable was meant "to show the hypocrisy and deceit of the Scribes and Pharisees, in pretending to works of righteousness, and not doing them." The leaders had just refused to give an honest answer about John. Now Jesus invited them to give an honest answer about two sons.

Jesus told the rest of the story. The first son said, "I will not: but afterward he repented, and went." The second said, "I go, sir: and went not" (Matthew 21:29-30). Then He asked, "Whether of them twain did the will of his father?" and the leaders answered, "The first" (Matthew 21:31). Jesus applied their answer to them: the publicans and harlots believed John, "and ye, when ye had seen it, repented not afterward, that ye might believe him" (Matthew 21:31-32).

The father calls his son teknon, which Thayer defines as "a child" and notes is used in "affectionate address." The command is warm, not harsh: "Son, go work to day in my vineyard." The second son's polite reply, "I go, sir," makes his failure to go all the sharper (Matthew 21:30).

Gill takes the man in the parable to be God, and the vineyard to be "the kingdom of God, or of heaven, the Gospel church state." Only Matthew records this parable.

God often teaches by asking. Jesus uses the same kind of opening elsewhere in Matthew: "How think ye?" (Matthew 18:12) and "What think ye of Christ?" (Matthew 22:42). A question invites people to think for themselves, and here it lets the leaders see the truth before they can defend against it.

The parable also shows the Father's heart. He asks both sons to work in his vineyard, and the son who first refused could still turn and go. Matthew Henry writes that it often happens that "the daring rebel is brought to repentance and becomes the Lord's servant, while the formalist grows hardened in pride and enmity." God is looking for obedience that follows through, and His door is open to those who turn around.