Narrated by Abu Bakra (Radhiallaho anho):

Allah's Messenger (sallallaahu 'alaihi wasallam) delivered to us a sermon on the Day of Nahr. He said, "Do you know what is the day today?" We said, "Allah and His Apostle know better." He remained silent till we thought that he might give that day another name. He said, "Isn't it the Day of Nahr?" We said, "It is." He further asked, "Which month is this?" We said, "Allah and His Apostle know better." He remained silent till we thought that he might give it another name. He then said, "Isn't it the month of Dhul-Hijja?" We replied: "Yes! It is." He further asked, "What town is this?" We replied, "Allah and His Apostle know it better." He remained silent till we thought that he might give it another name. He then said, "Isn't it the forbidden (Sacred) town (of Makkah)?" We said, "Yes. It is." He said, "No doubt, your blood and your properties are sacred to one another like the sanctity of this day of yours, in this month of yours, in this town of yours, till the day you meet your Lord. No doubt! Haven't I conveyed Allah's message to you? They said, "Yes." He said, "O Allah! Be witness. So it is incumbent upon those who are present to convey it (this information) to those who are absent because the informed one might comprehend it (what I have said) better than the present audience, who will convey it to him. Beware! Do not renegade (as) disbelievers after me by striking the necks (cutting the throats) of one another."

- Sahih Al-Bukhari