It is reported on the authority of Abu Dharr that he heard the Messenger of Allah (may peace and blessings be upon him) saying:No person who claimed knowingly anyone else as his father besides (his own) committed nothing but infidelity, and he who made a claim of anything, which (in fact) did not belong to him, is not amongst us; he should make his abode in Fire, and he who labeled anyone with unbelief or called him the enemy of Allah, and he was in fact not so, it rebounded on him.
وَحَدَّثَنِي زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا عَبْدُ الصَّمَدِ بْنُ عَبْدِ الْوَارِثِ، حَدَّثَنَا أَبِي، حَدَّثَنَا حُسَيْنٌ الْمُعَلِّمُ، عَنِ ابْنِ بُرَيْدَةَ، عَنْ يَحْيَى بْنِ يَعْمَرَ، أَنَّ أَبَا الأَسْوَدِ، حَدَّثَهُ عَنْ أَبِي ذَرٍّ، أَنَّهُ سَمِعَ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " لَيْسَ مِنْ رَجُلٍ ادَّعَى لِغَيْرِ أَبِيهِ وَهُوَ يَعْلَمُهُ إِلاَّ كَفَرَ وَمَنِ ادَّعَى مَا لَيْسَ لَهُ فَلَيْسَ مِنَّا وَلْيَتَبَوَّأْ مَقْعَدَهُ مِنَ النَّارِ وَمَنْ دَعَا رَجُلاً بِالْكُفْرِ أَوْ قَالَ عَدُوَّ اللَّهِ . وَلَيْسَ كَذَلِكَ إِلاَّ حَارَ عَلَيْهِ " .
Muslim
The Book of Faith • Hadith 123