Sahih Bukhari Volume 3, Book 30, Hadith Number 93.

Narated By Abu Huraira : The Prophet said, “I have made Medina a sanctuary between its two (Harrat) mountains.” The Prophet went to the tribe of Bani Haritha and said (to them), “I see that you have gone out of the sanctuary,” but looking around, he added, “No, you are inside the sanctuary.”