Sunan an-Nasa’i 4641
The Book of Financial Transactions
A Sale In Which There Is A condition And Both The Sale and The Condition Are Valid.
It was narrated that Jabir bin 'Abdullah said: "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 (ﷺ) 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 (ﷺ) 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.