[Machine] The Messenger of Allah ﷺ said, "If it were not for the fact that you are a messenger, I would have killed you," meaning the messenger of Musaylimah.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ «لَوْلَا أَنَّكَ رَسُولٌ لَقَتَلْتُكَ» يَعْنِي رَسُولَ مُسَيْلِمَةَ  

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 Messenger of Allah ﷺ 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). (Using translation from Abū Dāʾūd 2762)  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ «لَوْلَا أَنَّكَ رَسُولٌ لَضَرَبْتُ عُنُقَكَ وَأَنْتَ الْيَوْمَ لَسْتَ بِرَسُولٍ» فَأَمَرَ قَرَظَةَ بْنَ كَعْبٍ فَضَرَبَ عُنُقَهُ فِي السُّوقِ ثُمَّ قَالَ «مَنْ أَرَادَ أَنْ يَنْظُرَ إِلَى ابْنِ النَّوَّاحَةِ فَلْيَنْظُرْ إِلَيْهِ قَتِيلًا فِي السُّوقِ»