Musnad Abu Ya'la al-Mawsili 152:153

Abu Khaythama narrated to us, Muhammad ibn Khazim narrated to us, al-A’mash narrated to us, from Abu Ishaq, from Harithah ibn Mudarrib, who said: Abdullah said to Ibn al-Nawwahah: I heard the Messenger of Allah, may Allah bless him and grant him peace, say: "Were it not that you are a messenger, I would have killed you. But as for today, you are not a messenger. Stand up, O Khirashah, and strike his neck."