Sahih Muslim Book 32, Hadith Number 6253.
Chapter : It is forbidden to commit oppression.
Abu Musa reported Allah’s Messenger (may peace be upon him) as saying: Allah, the Exalted and Glorious, grants respite to the oppressor. But when He lays Hand upon him, He does not then let him off. Re (the Holy Prophet) then recited this verse: “Such is the chastisement of thy Lord when He chastises the towns (inhabited by) wrongdoing persons. Surely, His punishment is painful, severe”(xi.103).