Which of the two did the will of his father?
They said unto him, The first. Jesus said unto them,
Verily I say unto you, That the tax collectors and the harlots go into the kingdom of God before you.
All Commentaries on Matthew 21:31 Go To Matthew 21
Hilary of Poitiers
The first son represents the people who are from the Pharisees. Urgently admonished by God through the prophecy of John to conform themselves to his commandments, they remained insolent, disobedient and contemptuous to God’s warnings. They put their faith in the law and despised repentance from sin, glorying instead in the noble prerogative that they had from Abraham. Later they came to believe through the miracles worked by the apostles after the resurrection of the Lord, and, having returned by a faithful act of the will to evangelical works, they repented and confessed the guilt of their former insolence. The second son represents the group of publicans and sinners who later returned to the sinful state in which they lived at the time. They were instructed by John to expect salvation from Christ and to be baptized and to believe in him. When the Lord says in the parable that the second son did not go as he promised to do, he shows that these people believed John. But because they were not able to receive the teaching of the gospel through the apostles until after the Lord’s Passion (for it was then that the mysteries of human salvation were to be accomplished), they did not go. He didn’t say that they refused to go but simply that they did not go. Their failure to go does not make them guilty of disbelief, because to do so would have been very difficult. Therefore it is not that the second son did not want to do immediately what he was ordered to do but rather that he was unable to do it. His will is shown free from guilt by the obstacles of the circumstance.