The Messenger of Allah ﷺ said, "Prompt your dying ones to say, 'There is no god but Allah.'"
قال رسول الله ﷺ: لقنوا هلكاكم قول لا إله إلا الله.
Nasai (1827) narrated it from Ibrahim bin Yaqub, who said, Ahmad bin Ishaq narrated to me, who said, Wahib narrated to us, who said, Mansur bin Safiya narrated to us, from his mother Safiya bint Shayba, from Ayesha, and he mentioned the hadith. Its isnad is sahih.