Musnad Ahmad 33:341

'Abd al-Razzaq narrated to us, Ma'mar informed us, from Ibn Khuthaym, from Abu al-Zubayr, from Jabir, who said: The Messenger of Allah (peace and blessings of Allah be upon him) stayed in Makkah for ten years, following people in their dwellings at 'Ukaz and Majannah, and during the seasons at Mina, saying: "Who will give me shelter? Who will support me so that I may convey the message of my Lord, and for him is Paradise?" So much so that a man would come from Yemen or from Mudar—he said it like that—and his people would come to him and say: "Beware of the youth of Quraysh, lest he seduce you." He would walk among their men, and they would point at him with their fingers, until Allah sent us to him from Yathrib. We sheltered him and believed him. A man among us would go out, believe in him, and he would teach him the Qur'an, then he would return to his family, and they would embrace Islam through his Islam, until there remained no house among the houses of the Ansar except that there was a group of Muslims in it, manifesting Islam. Then they all consulted together, and we said: "Until when shall we leave the Messenger of Allah (peace and blessings of Allah be upon him) to be driven away in the mountains of Makkah and be in fear?" So seventy men among us set out to him until they came to him during the season. We made an appointment with him at the mountain pass of al-'Aqabah. We gathered with him, one man and two men, until we were all present. We said: "O Messenger of Allah, upon what shall we pledge allegiance to you?" He said: "You pledge allegiance to me to listen and obey in times of energy and laziness, to spend in times of hardship and ease, to enjoin the good and forbid the evil, to speak for the sake of Allah, not fearing the blame of any blamer for the sake of Allah, and that you will support me and protect me when I come to you, just as you protect yourselves, your wives, and your children, and for you is Paradise." He said: So we stood up to him and pledged allegiance to him. As'ad ibn Zurarah took his hand—and he was the youngest of them—and said: "Slowly, O people of Yathrib! For we did not strike the flanks of the camels except while we knew that he is the Messenger of Allah (peace and blessings of Allah be upon him). Indeed, taking him out today is a separation from all the Arabs, the killing of your best men, and that swords will bite you. So either you are a people who will be patient with that, and your reward is with Allah, or you are a people who fear for yourselves, so make that clear, for it is more excusable for you before Allah." They said: "Move away from us, O As'ad, for by Allah, we will never abandon this pledge, and we will never be stripped of it." He said: So we stood up to him and pledged allegiance to him, and he took from us [the pledge] and stipulated conditions, and he gave us in return for that Paradise.