Sahih Adab al-Mufrad

It is narrated from Aslam that Sayyiduna Umar (may Allah be pleased with him) used to say from the pulpit: O people, put your houses in order and scare away these snakes before they scare you. Surely, their being Muslims will never be apparent to you, and by Allah! Since we have become hostile to them, we have never reconciled with them.