Is one who affiliates with a tribe other than his own like one who affiliates with a father other than his own? Does this constitute apostasy that expels one from the faith, or does it necessitate repentance? Does repentance include informing everyone who was lied to about the true origin?

It is forbidden for a Muslim to ascribe himself to a tribe other than his own, due to the saying of the Prophet, peace and blessings be upon him: "No man claims to belong to other than his father, while he knows it, except that he has committed an act of disbelief (kufr). And whoever claims a kinship with people among whom he has no lineage, let him take his seat in the Fire." This disbelief is minor disbelief, and it indicates that the action is one of the major sins. Whoever has done this must repent to Allah Almighty from the lying and the false ascription, and tell the truth if asked about his origin. He is not obliged to inform those to whom he lied.