The last time I ever looked upon the Messenger of Allah ﷺ was when he drew back the curtain on Monday. I gazed at his face, which was like a page of the Quran, while the people were praying behind Abu Bakr. Abu Bakr made to move from his place, but the Prophet ﷺ gestured to him to stay where he was, then he let the curtain fall. He passed away by the end of that day.
حدثنا هشام بن عمار حدثنا سفيان بن عيينة عن الزهري سمع
آخر نظرة نظرتها إلى رسول الله ﷺ كشف الستارة يوم الاثنين فنظرت إلى وجهه كأنه ورقة مصحف والناس خلف أبي بكر في الصلاة فأراد أن يتحرك فأشار إليه أن اثبت وألقى السجف ومات من آخر ذلك اليوم
Bukhari narrated it in the Book of Adhan, chapter "People of knowledge and excellence are more entitled to lead the prayer," hadith no. 680, and Muslim narrated it in the Book of Prayer, chapter "The imam appointing a deputy...," hadith no. 419, both through various routes from Zuhri, at length and in summary form.