The Messenger of Allah ﷺ said, "Prompt your dying ones to say, 'There is no god but Allah.'"
حدثنا أبو بكر بن أبي شيبة حدثنا أبو خالد الأحمر عن يزيد بن كيسان عن أبي حازم
قال رسول الله ﷺ لقنوا موتاكم لا إله إلا الله
No references are available.
Reported by Muslim in the Book of Funerals, chapter on prompting the dying to say "There is no god but Allah," hadith no. 917, on the authority of Abu Bakr bin Shayba and others, with this wording.