It is narrated from Sayyiduna al-Irbad bin Sariyah (may Allah be pleased with him), who was from Banu Sulaym and among the People of the Suffah, that one day the Messenger of Allah (peace and blessings be upon him) came out to us and admonished the people, encouraging them and also warning them (of an evil end). Then he (peace and blessings be upon him) said: "Worship Allah and do not associate anything with Him; obey the one whom Allah has put in charge of your affairs; and do not dispute authority with those who hold it, even if he is an Abyssinian slave. It is binding on you to hold to what you know of the Sunnah of your Prophet and the way of the rightly guided caliphs (al-Khulafa' al-Rashidun), and to hold firmly to this truth with your molar teeth." This chain is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), and I know of no hidden defect ('illah) in it.