Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
muslim:59d – Abū Naṣr al-Tammār And ʿAbd al-Aʿlá b. Ḥammād > Ḥammād b. Salamah > Dāwud b. Abū Hind > Saʿīd b. al-Musayyab > Abū Hurayrah

even if he observed fast and prayed and asserted that he was a Muslim.  

مسلم:٥٩d – وَحَدَّثَنِي أَبُو نَصْرٍ التَّمَّارُ وَعَبْدُ الأَعْلَى بْنُ حَمَّادٍ قَالاَ حَدَّثَنَا حَمَّادُ بْنُ سَلَمَةَ عَنْ دَاوُدَ بْنِ أَبِي هِنْدٍ عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ عَنْ أَبِي هُرَيْرَةَ قَالَ

قَالَ رَسُولُ اللَّهِ ﷺ بِمِثْلِ حَدِيثِ يَحْيَى بْنِ مُحَمَّدٍ عَنِ الْعَلاَءِ ذَكَرَ فِيهِ وَإِنْ صَامَ وَصَلَّى وَزَعَمَ أَنَّهُ مُسْلِمٌ