It has been narrated on the authority of Anas b. Malik that it was said to the Prophet (ﷺ):
Would that you approached Abdullah b. Ubayy (to persuade him to accept Islam). The Prophet (ﷺ) (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 Prophet (ﷺ) 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 (ﷺ) 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.