Corban is a word that comes from Hebrew (korban). In the Bible, it appears only in Mark 7:11. In this verse, Mark explains that corban means something that is given to God as an offering.
Making something corban was a very serious choice. The Mishnah (a collection of Jewish oral laws and traditions) explains that once something was declared corban, this decision was rarely changed (Mishnah, Nedarim 5). Breaking a corban vow was considered very serious because people believed God would punish them.
In Mark 7, Jesus rejects the teaching of the scribes. The scribes taught that by the law a son could deny his parents from gaining any benefit from his property. To do this the son would state his property was “corban to them.” This practice goes against God's command to honor your parents (Exodus 20:12). The Jewish teachers' rules about corban were conflicting with God's law given through Moses.
Even if a son later felt sorry and wanted to help his parents, the Jewish religious leaders would not allow him to take back his corban declaration (Mark 7:12; compare Numbers 30:1–2).