I saw the Messenger of Allah ﷺ when he was dying. Beside him was a cup of water. He would dip his hand into the cup and wipe his face with the water, then say, "O Allah, help me through the agonies of death," or, "the throes of death."
حدثنا قتيبة حدثنا الليث عن ابن الهاد عن موسى بن سرجس عن القاسم بن محمد
رأيت رسول الله ﷺ وهو بالموت وعنده قدح فيه ماء وهو يدخل يده في القدح ثم يمسح وجهه بالماء ثم يقول اللهم أعني على غمرات الموت أو سكرات الموت
[Its isnad is hasan] Ibn Majah also reported it, Book of Funerals, chapter on what has been said about the mention of the Messenger of Allah's illness, no. 1623, from the hadith of Layth bin Saad, with the same wording. Hakim graded it sahih, 2/465, 3/56, 57, and Dhahabi agreed. Musa bin Sarjis has a hasan hadith, as mentioned in Tasheel al-Hajah.