for otherwise their words [and deeds] (1) could no longer be trusted, thereby nullifying the purpose of the prophetic mission.
Then, after the Messenger’s death, He caused the imamate to succeed the prophetic mission and appointed infallible leaders (2), so that people would be secure from their mistakes, lapses, and errors and would therefore submit to their commands, lest Allah leave the world bereft of His gracious care and mercy.
They also maintain that when Allah sent Muhammad (3)—may Allah bless him and grant him peace—(4), he undertook to convey (5) the message and explicitly declared that the caliph after him would be Alī ibn Abī Tālib [peace be upon him] (6); thereafter, he designated his son (7), al-Hasan al-Zakī, (8 then his son al-Husayn the Martyr 8) (8); then Alī ibn al-Husayn, Zayn al-Ābidīn; then Muhammad ibn Alī al-Bāqir; then Jafar ibn Muhammad al-Sādiq; then Mūsā ibn Jafar al-Kāzim; then Alī ibn Mūsā al-Ridā; then Muhammad ibn Alī al-Jawād; then Alī ibn Muhammad al-Hādī; then al-Hasan ibn Alī al-Askarī; then the successor, the Proof,