This article examines the chain of transmission (isnād) of the narration concerning Ziyārat al-Arbaʿīn, which forms the primary basis for the recommendation of visiting Imam al-Ḥusayn on the twentieth of Ṣafar. The study begins by presenting the full chain as reported by Shaykh al-Ṭūsī and then addresses objections raised regarding its completeness and the reliability of certain transmitters. Particular attention is given to Saʿdān b. Muslim and Muḥammad b. ʿAlī b. Maʿmar, whose reliability is not explicitly established in biographical sources but may be supported through indirect indicators, such as their association with recognised transmitters. The article also analyses chronological inconsistencies within the chain, especially the apparent gap between transmitters of different generations, suggesting the possibility of a missing intermediary. This leads to a proposed correction of the transmission wording, whereby a conjunction is interpreted as a transmission marker, thereby restoring coherence to the chain. Despite these efforts, the study concludes that issues remain within the isnād, particularly concerning certain narrators whose reliability cannot be fully established, leaving the question of the chain’s validity open to further scholarly consideration.