Sahih Muslim Book 7, Hadith Number 3167.

Chapter : Eminence of Medina, Allah’s Apostle (may peace be upon him) showered blessings upon it. Its sacredness and unlawfulness of hunting and lopping of trees and demarcation its precincts.

A Hadith like this has been narrated on the authority of A’mash with the same chain of transmitters, but no mention has been made of the Day of Resurrection. But this addition is made: “The protection granted by Muslims is one and must be respected by the humblest of them. And he who broke the covenant made by a Muslim, there is a curse of Allah, of his angels, and of the whole people upon him, and neither an obligatory act nor a supererogatory act would be accepted from him as recompense on the Day of Resurrection.”