Imamate is not Rightfully Invested except In the Descendants of al-Ḥusayn to the Exclusion of the Descendants of al-Ḥasan عليهما السلام

Saʿd, from Muḥammad b. ʿĪsā b. ʿUbayd, from Ḥammād b. ʿĪsā, from ʿAbd al-Aʿlā b. Aʿyan, who said: “I heard Abā ʿAbd Allāh عليه السلام saying: “Allāh عز وجل specified ʿAlī عليه السلام for the testamentary charge of the Apostle of Allāh صلى الله عليه وعلى آله and what he was appointed to, and al-Ḥasan and al-Ḥusayn affirmed that for him. Then, he bequeathed that to al-Ḥasan, and al-Ḥusayn subordinated himself to al-Ḥasan عليهما السلام until the Ordinance was deposited to al-Ḥusayn without anyone contesting it. He possessed the same prior merit as the other (al-Ḥasan). After that, the right of succession belonged to ʿAlī b. al-Ḥusayn, as per the statement of Allāh تعالى: ﴾The blood relatives are more entitled to inherit from one another in the Book of Allāh﴿ [33:6], and there were none (entitled to the Imamate) after ʿAlī b. al-Ḥusayn عليه السلام except his lineal descendants, generation after generation.”