Sahih Bukhari Volume 004, Book 053, Hadith Number 404.

Narated By Ali : We did not, write anything from the Prophet except the Quran and what is written in this paper, (wherein) the Prophet said, "Medina is a sanctuary from (the mountain of) Air to so and-so, therefore, whoever innovates (in it) an heresy or commits a sin, or gives shelter to such an innovator, will incur the Curse of Allah. the angels and all the people; and none of his compulsory or optional good deeds of worship will be accepted And the asylum granted by any Muslim Is to be secured by all the Muslims even if it is granted by one of the lowest social status among them. And whoever betrays a Muslim in this respect will incur the Curse of Allah, the angels and all the people, and his compulsory and optional good deeds of worship will not be accepted. And any freed slave will take as masters (befriends) people other than his own real masters who freed him without taking the permission of the latter, will incur the Curse of Allah, the angels and all the people, and his compulsory and optional good deeds of worship will not be accepted."

Narrated Said: Abu Huraira once said (to the people), "What will your state be when you can get no Dinar or Dirhan (i.e. taxes from the Dhimmis)?" on that someone asked him, "What makes you know that this state will take place, O Abu- Hu raira?" He said, "By Him in Whose Hands Abu Huraira's life is, I know it through the statement of the true and truly inspired one (i.e. the Prophet)." The people asked, "What does the Statement say?" He replied, "Allah and His Apostle's asylum granted to Dhimmis, i.e. non-Muslims living in a Muslim territory) will be outraged, and so Allah will make the hearts of these Dhimmis so daring that they will refuse to pay the Jizya they will be supposed to pay."