Sahih Muslim
The Book of Faith (Kitab Al-Iman)
Book Number: 001 / Hadith Number: 124
It is narrated on the authority of Jarir b. 'Abdullah that the Apostle of Allah (may peace and blessings be upon him) asked him on the occasion of the Farewell Pilgrimage to make the people silent and then said: Do not return to unbelief after me by striking the necks of one another.