Musnad Ahmad 482:37

Ya'qub narrated to us, he said: My father narrated to us, from Ibn Ishaq, he said: Yazid ibn Abi Habib al-Masri narrated to me, from Abd al-Rahman ibn Shumasah al-Tujibi, he said: I heard Uqbah ibn Amir al-Juhani saying, while he was on the pulpit of Egypt: I heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: "It is not lawful for a man to sell over the sale of his brother until he leaves it."