It is narrated from Sayyiduna Buraydah (may Allah be pleased with him) that Sayyiduna Abu Bakr (may Allah be pleased with him) said: "I heard the Messenger of Allah (peace and blessings be upon him) saying: 'Kill the lone one (the one who separates himself from the community), whoever he may be among the people.'"
Imam al-Tabarani (may Allah have mercy on him) said: "This hadith is not narrated from Sayyiduna Abu Bakr (may Allah be pleased with him) except with this chain; Abbad bin Ya'qub (may Allah have mercy on him) is alone in narrating it."
Hadith Referenceالمعجم الأوسط / باب الميم / 5446
Hadith Gradingمحدثین:فيه صالح بن متيم لم يُعرف، وبقية رجاله ثقات
Hadith Takhrij«قال الهيثمي: وفيه صالح بن متيم ولم أعرفه وبقية رجاله ثقات «مجمع الزوائد ومنبع الفوائد، ج 6، ص 233»»