I heard the Messenger of Allah ﷺ delivering a sermon during the Farewell Pilgrimage while seated upon his she-camel Jadaa, his foot resting in the saddle's stirrup as he stretched himself up. He said, "Fear Allah your Lord, pray your five prayers, fast your month, pay the zakat on your wealth, and obey those in authority over you, and you will enter the Paradise of your Lord."
سمعت رسول الله ﷺ يخطب في حجة الوداع- وهو على الجدعاء، واضع رجله في غرز الرحل يتطاول- فقال: اتقوا الله ربكم، وصلوا خمسكم، وصوموا شهركم وأدوا زكاة أموالكم، وأطيعوا ذا أمركم، تدخلوا جنة ربكم.
Tirmidhi narrated it (616) from Musa bin Abdul-Rahman Kindi Kufi, who said, Zayd bin Hubab narrated to us, Muawiya bin Salih informed us, Salim bin Amir narrated to me, he said, I heard Abu Umama, and he mentioned it.I said to Abu Umama, "How long ago did you hear this hadith from the Messenger of Allah ﷺ?" He said, "I heard it when I was thirty years old."Its chain is sahih. Tirmidhi said, "Hasan sahih." Ibn Hibban also graded it sahih (4563), as did Hakim (1/9), and it is found in Musnad Imam Ahmad (22161), all of them narrating through Muawiya bin Salih, who said, Salim bin Amir informed me, and he mentioned it.Hakim said, "This is a hadith sahih according to the standard of Muslim, and we know of no defect in it, and the two of them (Bukhari and Muslim) did not include it, though both Bukhari and Muslim relied on the narrations of Salim bin Amir as evidence, and the rest of its narrators are reliable."The wording is "this is your affair," and in another version, "obey your commanders."