251—Muhammad informed us. He said: Ahmad ibn Uthman informed us. He said: Muhammad ibn Mahan narrated to us. He said: Abd al-Rahman ibn Mahdi narrated to us. He said: Abd Allah ibn al-Mubarak narrated to us, from al-Awzaʿi, who said: Umar ibn Abd al-Aziz said: “When you see people conferring privately about some matter of their religion, excluding the common people, then know that they are laying the foundations of misguidance.”