Musnad Ahmad 1153:94

Sufyan narrated to us, from al-Zuhri, from Ubayd Allah, from Aisha, who said—Sufyan said: I heard a long hadith from him, of which I do not remember except a little of its beginning—: We entered upon Aisha and said: "O Mother of the Believers, tell us about the illness of the Messenger of Allah, may Allah bless him and grant him peace." She said: "He became ill, and he began to blow [breath]. We began to liken his blowing to the blowing of one who eats raisins. He used to rotate among his wives. When his illness became severe, he asked their permission to be in the house of Aisha, and that they [the wives] would rotate to him, so they gave him permission." "The Messenger of Allah, may Allah bless him and grant him peace, entered upon me between two men, leaning upon them, one of whom was Abbas, and his feet were dragging on the ground." Ibn Abbas said: "Did I not tell you who the other one was?" He said: "No." He said: "He was Ali."