Musnad Ahmad 1119:8

'Abd al-Samad narrated to us, he said: Muhammad ibn Abi al-Malih al-Hudhali narrated to us, he said: Ziyad ibn Abi al-Malih narrated to me, from his father, from Abu Burdah, from 'Awf ibn Malik al-Ashja'i: That he was with the Prophet, peace and blessings of Allah be upon him, on a journey. He traveled with them the entire day, not untying a single knot for them, and his entire night, not untying a knot, except for prayer, until they descended in the middle of the night. He said: A man watched the Messenger of Allah, peace and blessings of Allah be upon him, when he placed his saddle. He said: So I reached him and looked, and I did not see anyone except that he was sleeping, nor a camel except that it had placed its chest on the ground and was sleeping. He said: So I stretched myself and looked where the Prophet, peace and blessings of Allah be upon him, had placed his saddle, but I did not see him in his place. So I went out stepping over the saddles until I went out to the people, then I proceeded on my way into the blackness of the night. I heard a sound, so I reached it, and behold, it was Mu'adh ibn Jabal and al-Ash'ari. I reached them and said: "Where is the Messenger of Allah?" Then there was a humming like the humming of a millstone. I said: "It is as if the Messenger of Allah, peace and blessings of Allah be upon him, is at this sound." They both said: "Sit, be silent." Then he proceeded a little, then he came until he reached us. We stood up to him and said: "O Messenger of Allah, we were alarmed when we did not see you, so we followed your tracks." He said: "Indeed, a comer came to me from my Lord and gave me the choice between having half of my nation enter Paradise, or the intercession, so I chose the intercession." We said: "We adjure you by Allah and by the companionship, make us among the people of your intercession." He said: "You are among them." Then we proceeded, and a man or two men would come, and he would inform them of what he had informed us of. They would adjure him by Allah and by the companionship to make them among the people of his intercession, and he would say: "Indeed, you are among them." Until the people reached him and crowded around him and said: "Make us among them." He said: "I call you to witness that it is for whoever dies from my nation not associating anything with Allah."