Zuhayr ibn Harb and Muhammad ibn al-Muthanna narrated to me, both from Yahya al-Qattan. Zuhayr said: Yahya narrated to us, from Ubaydullah, who said: Nafi' informed me, from Ibn Umar, from the Prophet, peace and blessings be upon him, who said: "A man shall not sell over the sale of his brother, nor shall he propose over the proposal of his brother, unless he gives him permission."