Ash-Shama'il Al-Muhammadiyah, Book 53, Hadith 370 (English) ⓘ

Qaasim bin Muhammad Radiyallahu 'Anhu reports that 'Aayeshah Radiyallahu 'Anha said: "I had seen Rasulullah Sallallahu 'Alayhi Wasallam at the time of his death, a cup of water was near him. He was putting his hands in the cup and wiping his face with it. (At the time of intense heat and unrest it calms one). Then he was reciting: 'O Allah help me in the difficulties of death'"

حَدَّثَنَا قُتَيْبَةُ ‏,‏ حَدَّثَنَا اللَّيْثُ، عَنِ ابْنِ الْهَادِ، عَنْ مُوسَى بْنِ سَرْجِسَ، عَنِ الْقَاسِمِ بْنِ مُحَمَّدٍ، عَنْ عَائِشَةَ، أَنَّهَا قَالَتْ‏:‏ رَأَيْتُ رَسُولَ اللهِ صلى الله عليه وسلم، وَهُوَ بِالْمَوْتِ وَعِنْدَهُ قَدَحٌ فِيهِ مَاءٌ، وَهُوَ يُدْخِلُ يَدَهُ فِي الْقَدَحِ، ثُمَّ يَمْسَحُ وَجْهَهُ بِالْمَاءِ، ثُمَّ يَقُولُ‏:‏ اللَّهُمَّ أَعِنِّي عَلَى مُنْكَرَاتِ أَوْ قَالَ‏:‏ عَلَى سَكَرَاتِ الْمَوْتِ‏.‏