The Book Pertaining to the Merits of the Companions (Allah Be Pleased With Them) of the Holy Prophet (May Peace Be Upon Him) (Kitab Al-Fada'il Al-Sahabah)
Muslim :: Book 31 : Hadith 6168
Abu Sa'id reported there was some altercation between Khalid b. Walid and Abd al-Rahman b. 'Auf and Khalid reviled him. Thereupon Allah's Messwger (may peace be upon him) said: None should revile my Companions. for if one amongst you were to spend as much gold as Uhud, it would not amount to as much as one mudd of one of them or half of it.