The Messenger of Allāh ﷺ said:
فَعَلَيْكُمْ بِسُنَّتِي وَسُنَّةِ الْخُلَفَاءِ الْمَهْدِيِّينَ الرَّاشِدِينَ تَمَسَّكُوا بِهَا وَعَضُّوا عَلَيْهَا بِالنَّوَاجِذِ وَإِيَّاكُمْ وَمُحْدَثَاتِ الأُمُورِ فَإِنَّ كُلَّ مُحْدَثَةٍ بِدْعَةٌ وَكُلَّ بِدْعَةٍ ضَلاَلَةٌ
You must stick to my Sunnah and the Sunnah of my rightly guided successors, hold to it and stick fast to it. Beware of newly invented matters, for verily, every newly invented matter is an innovation, and all innovation is misguidance.
— Narrated by al-ʿIrbāḍ ibn Sārīyah رضي الله عنه
Dalīl: Sunan Abū Dāwūd #4607, Sunan ibn Mājah #42, Jāmiʿ at-Tirmidhī #2676, Musnad Aḥmad #17144, Ṣaḥīḥ ibn Ḥibbān #102, al-Mustadrak ʿalá aṣ-Ṣaḥīḥayn 1/95, Irwā’ al-Ghalīl #2455, al-Arbaʾūn an-Nawawīyyah #28, Kitāb al-Arba’īn Ḥadīthān #8, Mishkāt al-Maṣābīḥ #165, Riyāḍ aṣ-Ṣāliḥīn #157, Jāmiʿ Bayān al-ʿĪlm wa al-Faḍlihi #1213, Sunan ad-Dārimī 1/44, Sharḥ Mushkil al-Athār #1186, al-Muʾjam al-Kabīr #617, Kitāb ash-Sharīʿah P. 47, Sharḥ as-Sunnah #102, Kitāb as-Sunnah (ibn Abī ʿAṣim) #31, Ṣaḥīḥ al-Jāmiʿ #2549
Ḥukm: Ḥasan Isnād (OC) | Ṣaḥīḥ to Imām al-Ḥākim an-Nishāpurī, Imām adh-Dhahabī, Shaykh al-Albānī, Shaykh Shuʾayb al-Arnā’ūṭī, Ṣaḥīḥ Isnād to Imām ibn ʿAbd al-Barr and Shaykh Zubayr ʿAlī Za’ī — Ḥasan Ṣaḥīḥ to Imām at-Tirmidhī, Ḥasan to Imām al-Baghawī