Muhammad ibn Omar al-Kashi

Abū ʿAmr Muḥammad ibn ʿUmar ibn ʿAbd al-ʿAzīz al-Kashshī, known as al-Kashshi or as Kashshi, was a Persian Twelver Shi'ite scholar specializing in biographical evaluation and hadith studies. He is the author of the Rijāl al-Kashshī, a major biographical work which ranks as one of the four main sources in the Shi'ite rijāl literature. Al-Kashshi's original work is now lost, but parts of it survive in an abridgement made by Shaykh Tusi (995-1067) called the Ikhtiyār maʿrifat al-rijāl.