Abu Dawud Book 8, Hadith Number 2756.

Narated By Abdullah ibn Mas’ud : Harithah ibn Mudarrib said that he came to Abdullah ibn Mas’ud and said (to him): There is no enmity between me and any of the Arabs. I passed a mosque of Banu Hanifah. They (the people) believed in Musaylimah. Abdullah (ibn Mas’ud) sent for them. They were brought, and he asked them to repent, except Ibn an-Nawwahah. He said to him: I heard the Apostle of Allah (PBUH) say: Were it not that you were not a messenger, I would behead you. But today you are not a messenger. He then ordered Qarazah ibn Ka’b (to kill him). He beheaded him in the market. Anyone who wants to see Ibn an-Nawwahah slain in the market (he may see him).