Abu Uthman says that I heard Hazrat Sa’d saying: My ears have heard this from the Prophet (peace be upon him) and my heart has preserved it, that whoever, in the state of Islam, attributes his fatherhood to someone other than his real father, knowing that he is not his father, then Paradise is forbidden for him. And Hazrat Abu Bakrah (may Allah be pleased with him) said: I too heard this from the Prophet (peace be upon him) with my own ears and preserved it in my heart.