Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) narrates: We were with the Prophet Muhammad (peace and blessings be upon him) in a battle. A man from among the Muhajirun struck a man from among the Ansar on his back (or foot), so the Ansari said: "O Ansar (come to my help)!" and the Muhajir said: "O Muhajirun (come to my help)!" The narrator says: The Prophet Muhammad (peace and blessings be upon him) heard this and asked: "What has happened?" The people informed him: A man from among the Muhajirun struck a man from among the Ansar, so the Ansari said: "O Ansar (come to my help)!" and the Muhajir also said: "O Muhajirun (come to my help)!" So the Prophet Muhammad (peace and blessings be upon him) said: "This is the behavior of the time of ignorance; leave it, for it is filthy." (When Abdullah bin Ubayy heard of this) Abdullah bin Ubayy said: "Have they done this? By Allah! When we return to Madinah, the honorable people will surely expel the lowly ones from there." Sayyiduna Jabir (may Allah be pleased with him) says: The Ansar were more numerous in Madinah, but when the Prophet Muhammad (peace and blessings be upon him) came to Madinah, the Muhajirun became more. Sayyiduna Umar (may Allah be pleased with him) said: "O Messenger of Allah, allow me to strike the neck of this hypocrite." The Prophet Muhammad (peace and blessings be upon him) said: "Leave him! Otherwise, people will say that Muhammad (peace and blessings be upon him) is killing his companions."