We were on a military expedition. Sufyan said that they considered it to be the expedition against Banu Mustaliq. A man from the Muhajirun kicked a man from the Ansar from behind. The Muhajiri called out, "To me, Muhajirun!" and the Ansari called out, "To me, Ansar!"The Prophet ﷺ heard this and said, "What is this call of the Days of Ignorance?"They said, "A man from the Muhajirun kicked a man from the Ansar from behind."The Messenger of Allah ﷺ said, "Leave it alone, for it is foul."Abdullah bin Ubayy bin Salul heard about this and said, "Have they really done that? By Allah, if we return to Medina, the mightiest among us will surely expel the lowliest from it."Umar said, "Messenger of Allah, let me strike off the neck of this hypocrite."The Prophet ﷺ said, "Leave him, lest people say that Muhammad kills his own companions."Someone other than Amr added that his son Abdullah bin Abdullah said to him, "By Allah, you will not return until you acknowledge that you are the lowly one and the Messenger of Allah ﷺ is the mighty one." And so he did.
حدثنا ابن أبي عمر حدثنا سفيان عن عمرو بن دينار سمع
كنا في غزاة قال سفيان يرون أنها غزوة بني المصطلق فكسع رجل من المهاجرين رجلا من الأنصار فقال المهاجري ياللمهاجرين وقال الأنصاري ياللأنصار فسمع ذلك النبي ﷺ فقال ما بال دعوى الجاهلية قالوا رجل من المهاجرين كسع رجلا من الأنصار فقال رسول الله ﷺ دعوها فإنها منتنة فسمع ذلك عبد الله بن أبي ابن سلول فقال أوقد فعلوها والله لئن رجعنا إلى المدينة ليخرجن الأعز منها الأذل فقال عمر يا رسول الله دعني أضرب عنق هذا المنافق فقال النبي ﷺ دعه لا يتحدث الناس أن محمدا يقتل أصحابه وقال غير عمرو فقال له ابنه عبد الله بن عبد الله والله لا تنقلب حتى تقر أنك الذليل ورسول الله ﷺ العزيز ففعل
Agreed upon [by Bukhari and Muslim]. Muslim reported it in the Book of Righteousness and Kinship Ties, chapter on helping one's brother whether he is a wrongdoer or wronged, hadith 2584, from Ibn Abu Umar. Bukhari reported it, hadith 4905, from the hadith of Sufyan bin Uyayna, through the same chain.