Mukhtasar Muslim

Sayyiduna Jabir (may Allah be pleased with him) says: We were with the Noble Prophet (peace and blessings be upon him) in a battle when a Muhajir struck an Ansari on the buttocks (either with his hand or with a sword). The Ansari called out, "O Ansar, come to help!" and the Muhajir called out, "O Muhajirin, come to help!" The Messenger of Allah (peace and blessings be upon him) said, "This is a call of the days of ignorance (Jahiliyyah)." The people said, "O Messenger of Allah! A Muhajir struck an Ansari on the buttocks." He (peace and blessings be upon him) said, "Leave this, for it is a filthy thing." This news reached Abdullah bin Ubayy (the hypocrite), so he said, "Did the Muhajirin do this? By Allah, when we return to Madinah, the honorable person among us will surely expel the lowly one from there." (God forbid, this hypocrite considered himself honorable and called the Messenger of Allah (peace and blessings be upon him) lowly.) Sayyiduna Umar (may Allah be pleased with him) said, "O Messenger of Allah! Allow me to strike the neck of this hypocrite." The Prophet (peace and blessings be upon him) said, "Leave him (O Umar)! Lest people say that Muhammad (peace and blessings be upon him) kills his companions." (Although that accursed one deserved it, the Prophet (peace and blessings be upon him) did not punish him out of wisdom.)