Mujahid bin Jabir مجاهد بن جبر · The Book of al-Bay'ah

"I came to the Messenger of Allah with my father Umayyah on the Day of the Conquest (of Makkah) and said: 'O Messenger of Allah, accept my father's pledge for emigration (Al-Hijrah).' The Messenger of Allah said: 'I will accept his pledge to fight in Jihad, for the emigration (Al-Hijrah) has ceased."'

the Messenger of Allah sent an army and appointed a man in charge of them. He lit a fire and said: "Enter it." Some people wanted to enter it, and other said: "We are trying to keep away from it." They mentioned that to the Messenger of Allah, and he said to those who had wanted to enter if: "If you had entered it you would have stayed there until the Day of Resurrection." And he spoke good words to…