Musnad Abu Ya'la al-Mawsili 209:90

Abu Khaythama narrated to us, Jarir ibn Abd al-Hamid narrated to us, from Mughira, from Umm Musa, who said: Umm Salama said: "By the One whom Umm Salama swears by, the person who had the most recent contact with the Messenger of Allah (may Allah bless him and grant him peace) was Ali." She said: "It was the morning he passed away. The Messenger of Allah (may Allah bless him and grant him peace) sent for him, and I believe he had a need he sent him for. She said: 'He began saying, morning after morning, "Has Ali come?" three times.'" She said: "So he came before the rising of the sun. When he came, we knew that he had a need for him, so we went out of the house, and we were visiting the Messenger of Allah (may Allah bless him and grant him peace) in the house of Aisha." She said: "I was the last of those who went out of the house, then I sat closest of them to the door. Ali leaned over him, and he was the last person to have contact with him, and he began whispering to him and speaking privately with him."