An Nasai: Hadith 4400

"We were traveling with the Messenger of Allah and I was riding a camel. The Messenger of Allah said to me: 'Will you sell it to me for such and such, may Allah forgive you?', I said, I said, 'Yes, it is yours, O Prophet of Allah.' He said: 'Will you sell it to me for such and such, may Allah forgive your?' I said: 'Yes, it is yours, O Prophet of "Allah.' He said: 'Will you sell it to me for such and such, may Allah forgives you?' I said: 'Yes, it is yours. '''(One of the narrators) Abu Nadrah said: "This became a phrase that was used by the Muslims: 'Do such and such, may Allah forgive you.