Musnad Ahmad 32:1613

Yazid ibn Harun narrated to us, he said: Humayd al-Tawil informed us, from Thabit al-Bunani, who said: "It reached us that the Prophet, peace and blessings of Allah be upon him, prayed behind Abu Bakr during the illness in which he died, sitting, wrapped in a garment—he said: I think he said a *burd* (striped cloak)—then he called Usama and leaned his back against his chest, then he said: 'O Usama, lift me up to you.'" Yazid said: "It was in the book that I had [attributed] to Anas, so he did not say 'from Anas,' and he rejected it, and he affirmed Thabit."