Musannaf Ibn Abi Shayba 28:214

Abu Mu'awiyah narrated to us, from al-A'mash, from Abu Ishaq, from Harithah ibn Mudarrib, who said: A man went out leading a horse of his, and he passed by the mosque of Banu Hanifah, so he prayed in it. Their imam recited to them the words of Musaylimah the Liar. He came to Ibn Mas'ud and informed him, so he sent for them. He came to them and asked them to repent, and they repented, except for Abdullah ibn al-Nawwahah. He said to him: "O Abdullah, 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 struck your neck. But as for today, you are not a messenger.'" "O Kharashah, stand up and strike his neck." So he stood up and struck his neck.