Sayyiduna Sa’d (may Allah be pleased with him) narrated that I heard the Prophet (peace and blessings of Allah be upon him) say: Whoever claims to be the son of anyone other than his (real) father, knowing that he is not his father, then Paradise is forbidden for him. Then this hadith was mentioned to Sayyiduna Abu Bakrah (may Allah be pleased with him), so he said: Both my ears heard this hadith from the Prophet (peace and blessings of Allah be upon him), and my heart has preserved it.