Muhammad ibn Umar al-Kashshi

Al-Kashshi's exact date of birth is unclear. However, he is known to have been a contemporary of Muhammad ibn Ya'qub al-Kulayni (864–941), author of the Kitāb al-Kāfī. Al-Kashshi and al-Kulayni shared a number of teachers such as Muhammad ibn Ismail al-Naysaburi,^[5] as well as some students such as Ibn Qulawayh. This would place al-Kashshi roughly in the same time period as al-Kulayni, i.e., somewhere between the middle of the 9th century and the middle of the 10th century.^[6][7]

He was born in city of Kesh or Kish (known today as Shahrisabz) in Transoxiana (today: Uzbekistan).^[8]

Al-Kashshi's works are all lost today. However, one work known as the Rijāl al-Kashshī survives in an abridgement made by Shaykh Tusi (995–1067), called the Ikhtiyār maʿrifat al-rijāl.^[9] This work deals with the biographical evaluation of hadith transmitters, the goal of which was to establish whether individual transmitters are to be regarded as trustworthy, and whether their narrations –one of the main sources of Islamic doctrine– should be accepted or rejected.^[10][11]

The Ikhtiyār maʿrifat al-rijāl ranks as one of the four most important works in the Shi'ite biographical (rijāl) literature.^[12][13]