Hadith 158

And from him (may Allah be pleased with him) who said: The Messenger of Allah (ﷺ) led us in prayer one day, then he turned to us with his face and gave us an eloquent admonition, from which tears flowed and hearts trembled. A man said: "O Messenger of Allah, it seems as if this is a farewell advice. So advise us." He (ﷺ) said: "I advise you to fear Allah, listen, and obey, even if a black Abyssinian slave becomes your leader. Indeed, whoever lives after me will see many differences. So, you must follow my Sunnah and the Sunnah of the rightly guided Caliphs. Hold fast to it and bite onto it with your molars. And beware of newly introduced matters, for every innovation is a misguidance, and every misguidance is a deviation."