The Messenger of Allah ﷺ said, "Prompt your dying ones to say, 'There is no god but Allah.'"
حدثنا بشر بن المفضل حدثنا عمارة بن غزية عن يحيى بن عمارة قال سمعت
قال رسول الله ﷺ لقنوا موتاكم قول لا إله إلا الله
Its isnad is sahih. Bishr bin Mufaddal is trustworthy, Umara bin Ghaziya is not objectionable, and Yahya bin Umara Mazini is trustworthy. Abu Dawud narrated the hadith in 3/190, no. 3117, in the Book of Funerals, in the chapter on prompting, as did Tirmidhi in 3/297, no. 976, and Nasai in 4/5, no. 1826, both similarly.