Virtues of Madinah
Bukhari :: Book 3 :: Volume 30 :: Hadith 93
Narrated 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."