Sahih Bukhari Volume 8, Book 81, Hadith Number 778.

Narrated By ‘Aisha : Usama approached the Prophet on behalf of a woman (who had committed theft). The Prophet said, “The people before you were destroyed because they used to inflict the legal punishments on the poor and forgive the rich. By Him in Whose Hand my soul is! If Fatima (the daughter of the Prophet) did that (i.e. stole), I would cut off her hand.”