(8) باب قَوْلِ النَّبِيِّ صلى الله عليه وسلم " لاَ تَرْجِعُوا بَعْدِي كُفَّارًا، يَضْرِبُ بَعْضُكُمْ رِقَابَ بَعْضٍ
Narrated Abu Bakra:
Allah's Messenger (ﷺ) addressed the people saying, "Don't you know what is the day today?" They replied, "Allah and His Apostle know better." We thought that he might give that day another name. The Prophet said, "Isn't it the day of An-Nahr?" We replied, "Yes. O Allah's Messenger (ﷺ)." He then said, "What town is this? Isn't it the forbidden (Sacred) Town (Mecca)?" We replied, "Yes, O Allah's Messenger (ﷺ)." He then said, "Your blood, your properties, your honors and your skins (i.e., bodies) are as sacred to one another like the sanctity of this day of yours in this month of yours in this town of yours. (Listen) Haven't I conveyed Allah's message to you?" We replied, "Yes" He said, "O Allah! Be witness (for it). So it is incumbent upon those who are present to convey it (this message of mine) to those who are absent because the informed one might comprehend what I have said better than the present audience who will convey it to him.)" The narrator added: In fact, it was like that. The Prophet (ﷺ) added, "Beware! Do not renegade as disbelievers after me by striking (cutting) the necks of one another."
Reference: Sahih al-Bukhari 7078
In-book reference: Book 92, Hadith 29
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 9, Book 88, Hadith 199