أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ أَنْبَأَنَا أَزْهَرُ، أَنْبَأَنَا ابْنُ عَوْنٍ، عَنْ إِبْرَاهِيمَ، عَنِ الأَسْوَدِ، عَنْ عَائِشَةَ، قَالَتْ يَقُولُونَ إِنَّ النَّبِيَّ صلى الله عليه وسلم أَوْصَى إِلَى عَلِيٍّ لَقَدْ دَعَا بِالطَّسْتِ لِيَبُولَ فِيهَا فَانْخَنَثَتْ نَفْسُهُ وَمَا أَشْعُرُ فَإِلَى مَنْ أَوْصَى قَالَ الشَّيْخُ أَزْهَرُ هُوَ ابْنُ سَعْدٍ السَّمَّانُ .
It was narrated that 'Aishah said: "They say that the Prophet (PBUH) 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. Translation Not Available
Book Ref: Sunan An Nisai Book 1 Hadith 33
Web Ref: Sunan An Nisai Vol 1 Book 1 Hadith 33