Musannaf Ibn Abi Shayba 27:428

Jarir ibn Abd al-Hamid narrated to us, from Mughira, from Umm Musa, from Umm Salama, who said: "By the One by whom I swear, Ali was indeed the person who had the most recent contact with the Messenger of Allah (may Allah bless him and grant him peace)." She said: "We visited the Messenger of Allah (may Allah bless him and grant him peace) on the day he passed away in the house of Aisha. The Messenger of Allah (may Allah bless him and grant him peace) began saying, morning after morning, 'Has Ali come?' repeatedly." She said: "And I think he had sent him on an errand." She said: "Then he came later, and we thought that he had a need for him, so we went out of the house and sat at the door. I was among those closest to the door." She said: "Then Ali leaned over him and began whispering to him and speaking privately with him. Then he passed away on that very day, so he was the person who had the most recent contact with him."