Hadith 911
`Aishah (May Allah be pleased with her) reported:
عن عائشة رضي الله عنها قالت: سمعت النبي صلى الله عليه وسلم الله عليه وسلم الله عليه وسلم وهو مستند إلي يقول: اللهم اغفر لي وارحمني وألحقني بالرفيق الأعلى" ((متفق عليه)).
While the Prophet (ﷺ) was reclining against me (during his last illness) I heard him saying: "Allahumma-ghfir li, warhamni, wa alhiqni bir Rafiqil-A`la (O Allah, forgive me, bestow Your Mercy on me and let me join with the exalted companions.'' [Al-Bukhari and Muslim].
In plain words
In his final illness the Prophet's own words reached upward, asking Allah for forgiveness, mercy, and to be joined with the highest and most honoured company.
Reference : Riyad as-Salihin 911 In-book reference : Book 6, Hadith 18