Hints that Ali (as) was the rightful Caliph
It was narrated that 'Aishah said:
"They say that the Prophet (ﷺ) made a will for 'Ali,[1] but he called for a basin in which to urinate, then he went flaccid suddenly (and died), so how could he leave a will?!" The Shaikh said: Azhar (one of the narrators) is Ibn Sa'd As-Samman. [1] Meaning, appointing him as the Khalifah.
Grade: Sahih (Darussalam)
Reference : Sunan an-Nasa'i 33
In-book reference : Book 1, Hadith 33