For Moses said, Honour thy father and thy mother; and, Whoso curseth father or mother, let him die the death: But ye say, If a man shall say to his father or mother, It is Corban, that is to say, a gift, by whatsoever thou mightest be profited by me; he shall be free. Mark 7:10-11
There seemed to be a problem in the time of Jesus with people seeking to avoid the financial responsibility of caring for their parents by telling them that they had made a vow and declared their resources "corban" meaning "dedicated to God." This was convenient because they could still use their resources until their death, when the money would then go to the Temple. And they could break the commandment to honor their parents using supposedly righteous pretenses. The quote below is a little technical, but helpful in understanding this passage.
"Honor your father and your mother (Exod. 20:12; Deut. 5.10; Cf. Lev. 9.3; 20.9; Deut. 27.16; Exod. 21.16.) The force of "honor you father, etc." juxtaposed with the oath of benefit, can be understood only if one realizes that the Rabbis interpreted "honor" as meaning providing the father and mother with the physical necessities and does not mean honor or respect as this term is understood in English.
What you have gained...given to God The translation does not convey the true meaning of this passage. The expression "given to God", in the Greek is doron, which translates the Heb. corban, "a sacrifice," as in Mark 7.11, which frequently, in Jewish literature, means an "oath." The text then should read, "If anyone tells his father or his mother Corban (a vow!) what you would have gained from me, (you shall not have that benefit), he does not honor his father."
"According to Pharisees, a vow must be kept since it is written in the Bible that a man should not break his word (Deut. 23.24; Num. 30.3). But if a man took a vow against biblical precept he must keep his vow and not observe the precept for which undoubtedly, according to them, he will be punished for not observing the precept....According to Jesus no vow can be taken against a biblical precept."
Zeitlin goes on and points out, "However, to avoid a clash between two commandments in the Bible, namely, “honor thy father and thy mother” and “he shall not break his word” if a man took a vow not to honor his father and mother, the Pharisees introduced a legal fiction by which he could absolve his vow. This is called in the Talmud hafarat nedarim. Thus according to the Pharisees, if a man takes a vow against a biblical precept his vow can be absolved."
(Zeitlin, The Pharisees and the Gospels, p. 265)