General Behavior (Kitab Al-Adab)
Dawud :: Book 41 : Hadith 4867
Narrated Jundub:
A desert Arab came and making his camel kneel and tethering it, entered the mosque and prayed behind the Apostle of Allah (peace_be_upon_him). When The Apostle of Allah (peace_be_upon_him) had given the salutation, he went to his riding beast and, after untethering and riding it, he called out: O Allah, show mercy to me and to Muhammad and associate no one else in Thy mercy to us. The Apostle of Allah (peace_be_upon_him) then said: Do you think that he or his camel is farther astray? Did you not listen to what he said? They replied: Certainly.