The Prophet ﷺ said to me during the Farewell Pilgrimage, "Call the people to silence." Then he said, "Do not return after me to disbelief, striking one another's necks."
قال لي النبي ﷺ في حجة الوداع: استنصت الناس ثم قال: لا ترجعوا بعدي كفارا يضرب بعضكم رقاب بعض.
Bukhari narrated it in the Book of Military Expeditions (4405), and Muslim in the Book of Faith (65), both through the route of Shubah, from Ali bin Mudrak, who heard Abu Zura (that is, Ibn Amr bin Jareer) narrating from his grandfather Jareer, and he mentioned it. The wording given is that of Muslim.