Narrated from Sayyiduna Abu Dharr (may Allah be pleased with him) that he heard the Noble Prophet (peace and blessings of Allah be upon him) say: "Whoever knowingly claims someone other than his father as his father, he has committed disbelief. Whoever claims to belong to a people to whom he does not belong, let him take his place in the Hellfire."
Sayyiduna Wathilah bin Al-Asqa’ (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings of Allah be upon him) said: “The greatest slander (and most severe lie) is that a man claims someone other than his father as his father, or says he saw in a dream what his eyes did not see, or attributes to the Messenger of Allah (peace and blessings of Allah be upon him) something which he did not say.”