ANSWER: Mark 7 is the only place in the Bible where Jesus makes comments regarding the issue of Corban. His comments are a response to some self-righteous religious leaders who criticized his disciples for failing to wash, ceremonially, their hands before eating. After condemning them for their hypocrisy and "clever" methods of nullifying the laws of God so that they can keep their "cherished" traditions, he says the following.
For Moses commanded, (it was God who commanded through Moses), 'Respect your father and your mother' . . . But you teach that if people have something they could use to help their father or mother, but say, 'This is Corban' . . . they are excused . . . (Mark 7, verses 10 to 12)
Jesus was condemning the general practice of the Pharisees of bypassing God's laws and substituting them with their own traditions through Corban. The case you cite is one of the many Jesus was denouncing.
The Treasury of Scriptural Knowledge says that this practice was common among the Jews. The Pharisees would release by their own power a child from supporting his parents. Amazingly, according to the TSK, these religious leaders would deem it sacrilege if such a person afterwards decided to go ahead and support those who gave birth to him.
Easton's Bible Dictionary goes further on to state that this practice was considered a temple offering set aside or dedicated to God. A person could not reclaim anything given this designation. The dictionary also states that Jesus hated this practice of the Pharisees, as their traditions in this area nullified God's commandment that children should honor their parents. Their teaching gave people an excuse for not helping their father or mother and at the same time offered them the opportunity to use such designated good for their own selfish use.
God has instituted the fifth commandment for the explicit purpose of honoring one's parents (Exodus 20:12). Unfortunately, human beings have consistently tampered with God's instructions and this is one case. One of the ways to honor parents is by giving them financial support when in need, especially when they are in old age. Children were obliged to adhere to the law whether they loved their parents or not. However, with the permission of the Pharisees, they could circumvent part of the law by dedicating money meant for the parents to the temple. This is one example of how God's laws were made "of no effect" and overridden by religious tradition.
Today the practice of Corban is alive and well but modified for the modern world. Some professing Christian organizations do inculcate a loyalty to the church organization above loyalty to parents. In many groups where the bible is taught, dedication to a leader or denomination is leveraged as a means to increase the church coffers. Pressured members take whatever money might benefit their parents and redirect it "for the good of the church." It is amazing what expediency, convenience, or simply lack of righteousness can prompt people to do. It is the principle and attitude of justifying disobedience to God by adopting our own traditions that Jesus condemns.