Musnad Ahmad 930:11

Abdullah narrated to us, Sa’id ibn Muhammad al-Jarmi narrated to us—having come from Kufa—Abu Tumaylah narrated to us, ‘Isa ibn ‘Ubayd al-Kindi narrated to us, from al-Rabi’ ibn Anas, Abu al-‘Aliyah narrated to me, from Ubayy ibn Ka’b: That sixty-four of the Ansar were struck down on the day of Uhud, and six of the Muhajirun were struck down, along with Hamzah. They mutilated their dead. The Ansar said: "If we ever strike them one day in the future, we will surely exceed them in retaliation." When the day of the conquest of Makkah arrived, a man who was not known called out: "There is no Quraysh after today." Then Allah the Exalted revealed to His Prophet, may Allah bless him and grant him peace: "And if you punish, punish with an equivalent of that with which you were harmed" [An-Nahl: 126]. The Prophet of Allah, may Allah bless him and grant him peace, said: "Refrain from the people."