"They say that the Prophet (ﷺ) made a will for 'Ali, 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.

Meaning, appointing him as the Khalifah.

Sunan an-Nasa'i Book 1, Hadith 33