We were along with Messenger of Allah ﷺ in an expedition that a person from amongst the emigrants struck at the back of a person from the Ansir. The Ansiri said: O Ansar! And the Muhijir said: O Emigrants! Thereupon Messenger of Allah ﷺ said: What are these proclamations of the Days of Ignorance? They said: Messenger of Allah, a person from the emigrants struck at the back of an Ansari, whereupon he said: It is something disgusting. 'Abdullah b. Ubayy heard it and said: They have indeed done it. By Allah, when we would return to Medina the respectable amongst them (the Ansar) would turn away the mean (the emigrants). Thereupon 'Umar said: Permit me so that I should strike the neck of this hypocrite. But he (the Holy Prophet) said: Leave him, the people may not say that Muhammad kills his companions.  

سَمِعَ عَمْرٌو جَابِرَ بْنَ عَبْدِ اللَّهِ يَقُولُ كُنَّا مَعَ النَّبِيِّ ﷺ فِي غَزَاةٍ فَكَسَعَ رَجُلٌ مِنَ الْمُهَاجِرِينَ رَجُلاً مِنَ الأَنْصَارِ فَقَالَ الأَنْصَارِيُّ يَا لَلأَنْصَارِ وَقَالَ الْمُهَاجِرِيُّ يَا لَلْمُهَاجِرِينَ فَقَالَ رَسُولُ اللَّهِ ﷺ مَا بَالُ دَعْوَى الْجَاهِلِيَّةِ قَالُوا يَا رَسُولَ اللَّهِ كَسَعَ رَجُلٌ مِنَ الْمُهَاجِرِينَ رَجُلاً مِنَ الأَنْصَارِ فَقَالَ دَعُوهَا فَإِنَّهَا مُنْتِنَةٌ فَسَمِعَهَا عَبْدُ اللَّهِ بْنُ أُبَىٍّ فَقَالَ قَدْ فَعَلُوهَا وَاللَّهِ لَئِنْ رَجَعْنَا إِلَى الْمَدِينَةِ لَيُخْرِجَنَّ الأَعَزُّ مِنْهَا الأَذَلَّ قَالَ عُمَرُ دَعْنِي أَضْرِبْ عُنُقَ هَذَا الْمُنَافِقِ فَقَالَ دَعْهُ لاَ يَتَحَدَّثُ النَّاسُ أَنَّ مُحَمَّدًا يَقْتُلُ أَصْحَابَهُ  

[Machine] "A man from the Emigrants met a man from the Helpers (Ansar), so the Ansari man said, 'Oh, Helpers!' and the Muhajiri man said, 'Oh, Emigrants!' So the Messenger of Allah ﷺ said, 'What is the matter with people who revive the pre-Islamic practices? The call of ignorance (jahiliyyah) is an abhorrent thing.'"  

كَسَعَ رَجُلٌ مِنَ الْمُهَاجِرِينَ رَجُلًامِنَ الْأَنْصَارِ فَقَالَ الْأَنْصَارِيُّ يَا لَلْأَنْصَارِ وَقَالَ الْمُهَاجِرِيُّ يَا لَلْمُهَاجِرِينَ فَقَالَ رَسُولُ اللهِ ﷺ أَلَا مَا بَالُ دَعْوَى الْجَاهِلِيَّةِ دَعْوَى الْكَسْعَةَ فَإِنَّهَا مُنْتِنَةٌ  

We were in a Ghazwa (Sufyan once said, in an army) and a man from the emigrants kicked an Ansari man (on the buttocks with his foot). The Ansari man said, "O the Ansar! (Help!)" and the emigrant said. "O the emigrants! (Help!) Messenger of Allah ﷺ heard that and said, "What is this call for, which is characteristic of the period of ignorance?" They said, "O Messenger of Allah ﷺ! A man from the emigrants kicked one of the Ansar (on the buttocks with his foot)." Messenger of Allah ﷺ said, "Leave it (that call) as is a detestable thing." ʿAbdullah bin Ubai heard that and said, 'Have the (the emigrants) done so? By Allah, if we return Medina, surely, the more honorable will expel therefrom the meaner." When this statement reached the Prophet. ʿUmar got up an, said, "O Messenger of Allah ﷺ! Let me chop off the head of this hypocrite (ʿAbdullah bin Ubai)!" The Prophet ﷺ said "Leave him, lest the people say that Muhammad kills his companions." The Ansar were then more in number than the emigrants when the latter came to Medina, but later on the emigrant increased. (Using translation from Bukhārī 4905)   

كُنَّا مَعَ النَّبِيِّ ﷺ فِي غَزَاةٍ فَكَسَعَ رَجُلٌ مِنَ الْمُهَاجِرِينَ رَجُلًا مِنَ الْأَنْصَارِ فَقَالَ الْأَنْصَارِيُّ يَا لِلْأَنْصَارِ وَقَالَ الْمُهَاجِرِيُّ يَا لِلْمُهَاجِرِينَ فَسَمِعَ بِذَلِكَ النَّبِيُّ ﷺ فَقَالَ «مَا بَالُ دَعْوَى الْجَاهِلِيَّةِ؟» قَالُوا يَا رَسُولَ اللهِ رَجُلٌ مِنَ الْمُهَاجِرِينَ كَسَعَ رَجُلًا مِنَ الْأَنْصَارِ قَالَ رَسُولُ اللهِ ﷺ دَعُوهَا فَإِنَّهَا مُنْتِنَةٌ فَسَمِعَ بِذَلِكَ عَبْدُ اللهِ بْنُ أَبِي وَكَانَ مَعَهُمْ فِي الْغَزَاةِ فَقَالَ «أَوْ قَدْ فَعَلُوهَا وَاللهِ لَئِنْ رَجَعْنَا إِلَى الْمَدِينَةِ لَيُخْرِجَنَّ الْأَعَزُّ مِنْهَا الْأَذَلَّ فَقَامَ عُمَرُ» فَقَالَ يَا رَسُولَ اللهِ «دَعْنِي أَضْرِبْ عُنُقَ هَذَا الْمُنَافِقَ» قَالَ رَسُولُ اللهِ ﷺ «لَا يَتَحَدَّثُ النَّاسُ أَنَّ مُحَمَّدًا يَقْتَلُ أَصْحَابَهُ»