The Book of Occultation — al-Ṭūsī · Hadith 54 (#Ḥadīth #7)

ومنها انقراض هذه الفرقة فإنه لم يبق في الدنيا في وقتنا ولا قبله بزمان طويل قائل يقول به، ولو كان ذلك حقا لما جاز انقراضه.

Fourthly, this sect has become extinct. Not in our time, nor before us for a very long time, a believer of this creed has existed. If it were a true faith, its extinction would have been impossible.

Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).