Corban was an oath of a gift to the temple treasury. Sometimes the treasury was actually called Corban. The Jews developed a loop hole in the law to avoid giving financial support to their parents by basically saying, "I've already contributed to the temple and devoted that money to God."

After having devoted the gift to the temple it could not then be used for other purposes. Jesus was calling them to account for violating the 5th commandment to honor their parents, as the Hebrew word for "honor" is strong's H3513, "kabad" which means "heavy, to be honored, to be glorified, to be burdensome." (Biblehub)

The associated Greek word is G5091, "timao," and it bears the sense of such honor and valuable, significant, thus heavy.

The children were to provide for their parents and grandparents before burdening the treasury of the temple with their care. The Corban (Korban) was misused by disobedient children to avoid the financial needs of their parents.

Excerpt from Barne's Notes at Matt. 15:5 -

If he had once devoted his property once said it was "corban," or a gift to God - it could not be appropriated even to the support of a parent. If a parent was needy and poor, and if he should apply to a son for assistance, and the son should reply, though in anger, "It is devoted to God; this property which you need, and by which you might be profited by me, is "corban" - I have given it to God;" the Jews said the property could not be recalled, and the son was not under obligation to aid a parent with it. He had done a more important thing in giving it to God. The son was free. He could not be required to do anything for his father after that. (Biblehub)

Corban was an oath of a gift to the temple treasury. Sometimes the treasury was actually called Corban. The Jews developed a loop hole in the law to avoid giving financial support to their parents by basically saying, "I've already contributed to the temple and devoted that money to God."

After having devoted the gift to the temple it could not then be used for other purposes. Jesus was calling them to account for violating the 5th commandment to honor their parents, as the Hebrew word for "honor" is strong's H3513, "kabad" which means "heavy, to be honored, to be glorified, to be burdensome." (Biblehub)

The associated Greek word is G5091, "timao," and it bears the sense of such honor and valuable, significant, thus heavy.

The children were to provide for their parents and grandparents before burdening the treasury of the temple with their care. The Corban (Korban) was misused by disobedient children to avoid the financial needs of their parents.

Excerpt from Barne's Notes at Matt. 15:5 -

If he had once devoted his property once said it was "corban," or a gift to God - it could not be appropriated even to the support of a parent. If a parent was needy and poor, and if he should apply to a son for assistance, and the son should reply, though in anger, "It is devoted to God; this property which you need, and by which you might be profited by me, is "corban" - I have given it to God;" the Jews said the property could not be recalled, and the son was not under obligation to aid a parent with it. He had done a more important thing in giving it to God. The son was free. He could not be required to do anything for his father after that. (Biblehub)

The Christian perspective is not in view here as Jesus was speaking to scribes and Pharisees. They were Jews. The gospel had not yet been preached to the gentiles which happened in Acts 10. The converts, both Jew and gentile were not called Christian until Acts 11 at Antioch. It was the Jews He was addressing who were guilty of twisting and perverting the law of fifth commandment.

However, the fifth commandment is reinforced in the gospel of Christ for all Christians in Luke 18:20; Col. 3:20-21; 1 Tim. 5:8; and Eph. 6:2.