Narrated 'Abdullah bin 'Umar (ra): I bartered my property in Khaibar to 'Uthman (chief of the faithful believers) for his property in Al-Wadi. When we finished the deal, I left immediately and got out of his house lest he should cancel the deal, for the tradition was that they buyer and the seller had the option of canceling the bargain unless they separated. When out deal was completed, I came to know that I have been unfair to 'Uthman, for by selling him my land I caused him to be in a land of Thamud, at a distance of three days journey from Al-Madina, while he made me neared to Al-Madina, at a distance of three days journey from my former land.

Narrated Ibn `Umar: The Prophet said, "The buyer and the seller have the option to cancel or confirm the bargain before they separate from each other or if the sale is optional." Nafi` said, "Ibn `Umar used to separate quickly from the seller if he had bought a thing which he liked."

Narrated Ibn 'Umar (ra): We were in the company of the Prophet (saws) on a journey, and I was riding a troublesome camel. The Prophet (saws) asked 'Umar to sell that camel to him. So, 'Umar sold it to him. The Prophet (saws) then said, "O 'Abdullah! The camel is for you."