Musnad Ahmad 33:538

Ishaq ibn Isa narrated to us, Yahya ibn Sulaym narrated to us, from Abdullah ibn Uthman ibn Khuthaym, from Abu al-Zubayr, that Jabir ibn Abdullah narrated to him, that the Messenger of Allah (peace and blessings of Allah be upon him) remained for ten years following the pilgrims in their dwellings during the season, and at Majannah and Ukaz, and at their dwellings in Mina, saying: "Who will give me shelter? Who will support me so that I may convey the messages of my Lord, and for him is Paradise?" But he would not find anyone to support him or give him shelter. So much so that a man would travel from Mudar or from Yemen to his relatives, and his people would come to him and say: "Beware of the youth of Quraysh, lest he tempt you." He would walk among their camps, calling them to Allah (Mighty and Majestic is He), and they would point at him with their fingers. Until Allah (Mighty and Majestic is He) sent us to him from Yathrib. A man would come to him and believe in him, and he would teach him the Quran, and he would return to his family, and they would embrace Islam through his Islam, until there remained no house among the houses of Yathrib except that there was a group of Muslims in it who manifested Islam. Then Allah (Mighty and Majestic is He) sent us, so we consulted one another and gathered, seventy men of us. 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 we traveled until we came to him during the season, and we made an appointment with him at the mountain pass of al-Aqabah. His uncle al-Abbas said: "O son of my brother, I do not know who these people are who have come to you. I am knowledgeable of the people of Yathrib." We gathered with him, one man and two men. When al-Abbas looked at our faces, he said: "These are people I do not know; these are youths." 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 without fearing the blame of any critic, and that you will support me when I come to Yathrib, and protect me as you protect yourselves, your wives, and your children, and for you is Paradise." We stood to pledge allegiance to him. As'ad ibn Zurarah took his hand—and he was the youngest of the seventy—and said: "Slowly, O people of Yathrib! We did not strike the sides of our camels toward him except while we knew that he is the Messenger of Allah. His departure today is a separation from all the Arabs, the killing of your best men, and that swords will bite you. So if you are a people who can be patient against the swords when they touch you, and against the killing of your best men, and against the separation from all the Arabs, then take him, and your reward is with Allah. But if you are a people who fear for yourselves, then leave him, for that is more excusable before Allah." They said: "O As'ad ibn Zurarah, remove your hand from us, for by Allah, we will not abandon this pledge, nor will we ask to be released from it." So we stood to him, man by man, and he took from us the conditions of al-Abbas, and he gave us in return for that, Paradise.