The Messenger of Allah ﷺ said, "Prompt your dying ones to say, 'There is no god but Allah.'"
حدثنا مسدد حدثنا بشر حدثنا عمارة بن غزية حدثنا يحيى بن عمارة قال سمعت
قال رسول الله ﷺ لقنوا موتاكم قول لا إله إلا الله
Muslim narrated it in the Book of Funerals, in the chapter on prompting the dying to say "There is no god but Allah," hadith no. 916, from the hadith of Bishr bin Mufaddal, through this same chain.