I heard the Prophet ﷺ saying, "Whoever claims to be the son of a person other than his father, and he knows that person is not his father, then Paradise will be forbidden for him." I mentioned that to Abu Bakra, and he said, "My ears heard that and my heart memorized it from Messenger of Allah ﷺ.
سَمِعْتُ النَّبِيَّ ﷺ يَقُولُ مَنِ ادَّعَى إِلَى غَيْرِ أَبِيهِ وَهْوَ يَعْلَمُ أَنَّهُ غَيْرُ أَبِيهِ فَالْجَنَّةُ عَلَيْهِ حَرَامٌ فَذَكَرْتُهُ لأَبِي بَكْرَةَ فَقَالَ وَأَنَا سَمِعَتْهُ أُذُنَاىَ وَوَعَاهُ قَلْبِي مِنْ رَسُولِ اللَّهِ ﷺ