Musnad Abu Ya'la al-Mawsili 152:79

Abu Khaythama narrated to us, Jarir narrated to us, from Mughira, from Ibrahim, who said: Hani al-Dabbi said: We met Alqama, and Ziyad had mutilated a man and crucified him. He said to us: "For what have these people gathered?" I said: "Ziyad has mutilated a man." He said: Abdullah said, from the Prophet, peace and blessings of Allah be upon him—as I reckon—: "Indeed, the most restrained of people in killing are the people of faith."