Both he and his brother pursued the quest for knowledge side by side, and he died in middle age, some time before his brother.

Those who narrated from him include: his brother al-Ḥasan, Wakīʿ, ʿUbayd Allah ibn Mūsā, ʿAbd Allah ibn Dāwūd, Abū Nuʿaym, Khālid ibn Makhlad al-Qaṭawānī, Ismāʿīl ibn ʿAmr al-Bajali, and others.

His reports never became widely circulated because of his early death.

He was declared reliable by Aḥmad ibn Ḥanbal and Yaḥyā ibn Maʿīn, as we mentioned in the biography of his brother (1).

ʿAbd Allah ibn Mūsā said: “I heard al-Ḥasan ibn Ṣāliḥ say: ‘When my brother was at the point of death, he lifted his gaze and then recited: “…with those upon whom Allah has bestowed His favor—the prophets, the steadfast affirmers of truth, the martyrs, and the righteous. How excellent are those as companions” (Q 4:69). Then his soul departed. We looked and found a hole in his side that had reached into his body, yet no one had known of it.’”

I add: Both brothers were master reciters of the Quran, precise in their rendition. ʿAlī studied under ʿĀṣim and later under Ḥamzah. He later assumed the seat of instruction, and among those who recited to him were ʿUbayd Allah ibn Mūsā and others.

A single hadith from ʿAlī is recorded in Ṣaḥīḥ Muslim (2), dealing with good character.

He died in 154 AH.

He did not adopt his brother’s stance of boycotting the Friday prayer or any similar view.

As for the statement of Muḥammad ibn Muthannā al-Zamin, “I never saw ʿAbd al-Raḥmān ibn Mahdī transmit anything from ʿAlī ibn Ṣāliḥ,” this does not indicate any weakness on ʿAlī’s part; rather, ʿAbd al-Raḥmān never met him—or so I believe.