And he came to the second, and said likewise. And he answered and said, I go, sir: and went not.

People's New Testament

21:28-31 A certain man had two sons. The two sons represent the priests, elders and scribes on the one hand, and the publicans and harlots, the sinners, on the other (Mt 21:31). Both classes were bidden to work in the Lord's vineyard. The publicans and sinners had refused, but repented at the preaching of John. The others professed to obey, but did not. The design of the parable is to show that the publicans and harlots, whom they so much despised, were morally superior to his questioners.

Wesley's Notes

21:30 He answered, I go, sir: but went not - Just so did the scribes and Pharisees: they professed the greatest readiness and zeal in the service of God: but it was bare profession, contradicted by all their actions.

Jamieson-Fausset-Brown Bible Commentary

30. And he came to the second, and said likewise. And he answered and said, I go, sir-"I, sir." The emphatic "I," here, denotes the self-righteous complacency which says, "God, I thank thee that I am not as other men" (Lu 18:11).

and went not-He did not "afterward repent" and refuse to go; for there was here no intention to go. It is the class that "say and do not" (Mt 23:3)-a falseness more abominable to God, says Stier, than any "I will not."

Matthew Henry's Concise Commentary

21:28-32 Parables which give reproof, speak plainly to the offenders, and judge them out of their own mouths. The parable of the two sons sent to work in the vineyard, is to show that those who knew not John's baptism to be of God, were shamed by those who knew it, and owned it. The whole human race are like children whom the Lord has brought up, but they have rebelled against him, only some are more plausible in their disobedience than others. And 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.