Musnad Ahmad 1156:255

'Affan narrated to us, Hammam narrated to us, Qatadah narrated to us, from Abu al-Khalil, from Safinah, the freed slave of Umm Salamah, from Umm Salamah, that the Prophet (peace and blessings of Allah be upon him) said while he was in the throes of death: "The prayer, the prayer, and what your right hands possess." He began to repeat it, and his tongue could not articulate it clearly.