John Chrysostom

And since this had no shade of contrariety to the law, to command men to wash their hands, He brings forward another tradition, which is opposed to the law. And what He saith is like this. "They taught the young, under the garb of piety, to despise their fathers." How, and in what way? …

Homily on the Gospel of Matthew 51 ↗

Jerome

For God said, 'Honor your father and mother, and whoever curses his father or mother, let him be put to death.' But you say, 'Whoever says to his father or mother, Whatever help you would have received from me is given to God,' and does not honor his father or mother, you have made void the commandment of God because of your tradition. Hypocrites, well did Isaiah prophesy of you, saying, 'This people honors me with their lips, but their heart is far from me' (Exodus 20, Leviticus 20). …

Commentary on Matthew ↗

Thomas Aquinas

Then when he says for God said etc., he presents what this commandment is, which is about honoring parents. And first he presents the commandment; second, the punishment. Hence he says for God said: honor your father and your mother. And it should be noted that honor is nothing other than reverence shown in testimony of virtue. For he shows reverence who administers what is necessary; hence a man is bound not only to rise in respect, but also to provide necessities. Sir. 2:21: those who fear the Lord will keep his commandments. …

Commentary on Matthew ↗