Musannaf Ibn Abi Shayba 27:463

Abu Bakr ibn Ayyash narrated to us, from Sadaqah ibn Sa'id, from Jami' ibn Umayr, who said: I entered upon Aisha, along with my mother and my maternal aunt, and we asked her, "How was Ali in his [the Prophet's] estimation?" She said: "Are you asking me about a man who placed his hand in a position with the Messenger of Allah (may Allah bless him and grant him peace) that no one else had placed it? His soul departed while it was in his hand, and he wiped his face with it. And when he died, it was said, 'Where shall we bury him?' Ali said, 'There is no spot on earth more beloved to Allah than the spot in which He took the soul of His Prophet,' so we buried him there."