Shaykh Saduq's famous treatise on the core beliefs of Shi'a Islam and Shaykh Mufid's emendation
Al-Shaykh al-Saduq (Khorasan c. 923, Ñ Rayy 991) is the title given to Abu Ja'far Muhammad ibn 'Ali ibn Babawaih al-Qummi (___ __ ______ _____), or commonly known in English as Ibn Babawayh. He was the leading traditionist of his time (4th Century A.H.) and one of the most outstanding traditionists of Shi'ite Islam. He earned the title of al-Shaykh al-Saduq on account of his great learning and his reputation for truthfulness.