Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Amir that Hazrat Umar bought a horse from a man, and said, "If you are satisfied, then the price will be binding upon me, otherwise there will be no sale between us." Hazrat Umar (may Allah be pleased with him) had a person ride the horse in his presence, and the horse quickly became tired. Hazrat Shurayh was appointed as judge between them. Hazrat Shurayh said to Hazrat Umar (may Allah be pleased with him): "Hand over what you have bought, or return what you have taken." Hazrat Umar said to him: "You have judged with the bitter truth." Hazrat Amir states that he (Shurayh) was sent to Kufa for the position of judge, and Hazrat Ka'b bin Soor was sent to Basra for the position of judge.