Musnad Ahmad 877:0

Narrated to us by Bahz, narrated to us by Hammad, from Humayd, from Bakr ibn Abdullah, from the paternal uncle of Abu Hurrah al-Raqashi, that he was present at the Prophet (peace be upon him) during the middle of the days of Tashreeq, while he was upon his camel, and he said: "O people, do you know what day this is? And what month this is? And what land this is?" They said: "Allah and His Messenger know best." He said: "Indeed, your blood, your wealth, and your honor are sacred among you, like the sanctity of this day of yours, in this month of yours, in this land of yours. Have I conveyed?" They said: "Yes." He said: "O Allah, bear witness." Then he said: "Do not return after me as disbelievers, striking the necks of one another. Let the one who is present convey to the one who is absent, for perhaps the one to whom it is conveyed will understand it better than the one who heard it."