Jn 5: 33-36
You sent emissaries to John, and he testified to the truth.
I do not accept testimony from a human being, but I say this so that you may be saved.
He was a burning and shining lamp, and for a while you were content to rejoice in his light.
But I have testimony greater than John’s. The works that the Father gave me to accomplish, these works that I perform testify on my behalf that the Father has sent me.
Source: New American Bible
Catechism of the Catholic Church
582 Going even further, Jesus perfects the dietary law, so important in Jewish daily life, by revealing its pedagogical meaning through a divine interpretation: “Whatever goes into a man from outside cannot defile him. . . (Thus he declared all foods clean.). . . What comes out of a man is what defiles a man. For from within, out of the heart of man, come evil thoughts. . .”In presenting with divine authority the definitive interpretation of the Law, Jesus found himself confronted by certain teachers of the Law who did not accept his interpretation of the Law, guaranteed though it was by the divine signs that accompanied it. This was the case especially with the sabbath laws, for he recalls, often with rabbinical arguments, that the sabbath rest is not violated by serving God and neighbor, which his own healings did.
“The crown of the wise is resourcefulness; the diadem of fools is folly.”