Musnad Abu Ya'la al-Mawsili 6:12

Muhammad ibn al-Minhal narrated to us, Yazid ibn Zuray' narrated to us, Khalid narrated to us, from Abu Uthman al-Nahdi, who said: I spoke to Abu Bakrah and said: I heard Sa'd say: My two ears heard it and my heart retained it from Muhammad, may Allah bless him and grant him peace: "Whoever claims to be the son of someone other than his father in Islam, while he knows that he is not his father, then Paradise is forbidden to him." He said: And my two ears heard it and my heart retained it from Muhammad, may Allah bless him and grant him peace.