Musannaf Ibn Abi Shayba 21:213

Yunus ibn Muhammad narrated to us, Layth ibn Sa’d narrated to us, from Yazid ibn Abi Habib, from Musa ibn Sarjas, from al-Qasim ibn Muhammad, from Aisha, who said: I saw the Messenger of Allah, may Allah bless him and grant him peace, while he was dying, and beside him was a cup containing water. He would insert his hand into the cup and wipe his face with the water, then say: "O Allah, assist me against the agonies of death."