Church Fathers on Matthew 21:29

Thus much prefaced, the Lord brings forward a parable, to convict them of their irreligion, and shew them that the kingdom of God should be transferred to the Gentiles.

Those who are to be judged in this cause, He applies to as judges, that condemning themselves they might be shewn to be unworthy to be acquitted by any other. It is high confidence of the justness of a cause, that will entrust it to the decision of an adversary. But He veils the allusion to them in a parable, that they might not perceive that they were passing sentence upon themselves; 'A certain man had two sons.' Who is he but God, who created all men, who being by nature…

Whence we may gather, that in this parable the Lord spoke to such as promise little or nothing, but in their works shine forth; and against those who promise great things but do none of these things that they have promised.