From Sahih Bukhari (Hadith 4440):
Narrated `Aisha:I heard the Prophet (ﷺ) and listened to him before his death while he was leaning his back on me and saying, "O Allah! Forgive me, and bestow Your Mercy on me, and let me meet the (highest) companions (of the Hereafter)." (See the Qur'an (4:69) and Hadith
Reference: Bukhari 4440