Abu Hurayrah (may Allah be pleased with him) reported directly from the Prophet (may Allah's peace and blessings be upon him) that he said: “Do not disown your fathers. Whoever disowns his father has disbelieved.”
شرح الحديث :
Disowning one's father willingly is forbidden. This practice is similar to an act of disbelief. Actually, it is not the kind of disbelief that takes one to Hell forever. Rather, it is minor disbelief.