It was narrated that Ibn 'Abbas said:"A man came to him and said: 'I have made my wife forbidden to myself.' He said: 'You are lying, she is not forbidden to you.' Then he recited this Verse: 'O Prophet! Why do you forbid (for yourself) that which Allah has allowed to you.' (And he said): 'You have to offer the severest form of expiation: Freeing a slave