Sahih Muslim Book 19, Hadith Number 4433.

Chapter : About the Holy Prophet’s (may peace be upon him) calling for Allah’s help and his patience over the persecution of the hypocrites.

It has been narrated on the authority of Anas b. Malik that it was said to the Holy Prophet (may peace be upon him): Would that you approached Abdullah b. Ubayy (to persuade him to accept Islam). The Holy Prophet (may peace be upon him) (accordingly) went to him, riding a donkey, and (a party of) Muslims also went (with him). On the way they had to walk over a piece of land affected with salinity. When the Holy Prophet (may peace be upon him) approached him, he said: Do not come near me. By Allah, the obnoxious smell of your donkey has offended me (As a rejoinder to this remark), a man from the Ansar said: By God, the smell of the donkey of the Messenger of Allah (may peace be upon him) is better than your smell (At this), a man from the tribe of ‘Abdullah got furious. Then people from both sides got furious and exchanged blows with sticks, hands and shoes. (The narrator says) that (after this scuffle) we learnt that (the Qur’anic verse): “It two parties of the Believers have a quarrel, make ye peace between them” (xlix. 9) was revealed about these fighting parties.