An elementary commandment.

"For Moses said: Honor your father and your mother; and: He who speaks badly of his father or his mother, may he die; but you say: If a man says to the father or the mother: Anything of mine with which you could benefit is a corban (that is, an offering to God); you no longer let him do anything in favor of his father or his mother; thus invalidating the word of God for your tradition, which you have transmitted, and you do many things similar to these ."

Source

Now I was giving you an example of what they were doing. In the Law, one of God's commandments established that the father and mother should be honored. But human tradition allowed them to escape from that responsibility towards their parents. If a man did not wish to help his parents when they were older and were in need, he would devote his possessions or the resources necessary to support his parents to the priest in the temple. These resources were declared "corban", which meant an offering, a donation. Then, according to the tradition of the scribes, that man was exempt from that commandment of God and his parents were legally excluded from any claim against him. At the death of man, his heritage was left for the temple.
He was saying that the tradition was pernicious and contradicted the intention of the Law of God, which was to honor the father and the mother. And that was a responsibility that people had to fulfill.

Credits to the author Luis de Miguel of the Biblical school.