The Book on Government (Kitab Al-Imara)
Muslim :: Book 20 : Hadith 4593
It has been narrated by Salama b. al-Akwa' that he visited al-Hajjaj who said to him: O son of al-Akwa', you have turned apostate and have come to live again in the desert with the Bedouins (after your migration). He said: No, but the Messenger of Allah (may peace be upon him) has permitted me to live in the desert.