Sahih al-Bukhari 2825

ʿAmr ibn ʿAli narrated to us; Yahya narrated to us; Sufyan narrated to us, who said: Mansur told me, from Mujahid, from Tawus, from Ibn ʿAbbas (may Allah be pleased with them both), that on the day of the Conquest the Prophet said: “There is no emigration after the Conquest, but there is striving and intention. When you are called to mobilize, then go forth.”