Al-Saduq, also known as Abu Ja'far Muhammad ibn Ali ibn al-Husayn al-Saduq, was a prominent Islamic scholar and hadith compiler in the 10th century. He is best known for his works in the field of Shia Islam, particularly for his contributions to the collection and authentication of hadith, which are sayings and actions of the Prophet Muhammad. His most famous works include Man La Yahduruhu al-Faqih, a comprehensive collection of hadith that serves as a key reference for Shia jurisprudence. Al-Saduq's scholarship has had a lasting impact on Islamic thought, and he is respected for his efforts to preserve and transmit the teachings of Ahl al-Bayt, the family of the Prophet Muhammad.