Al-mustasfa min 'ilm al-usul (Arabic: المستصفى من علم الأصول‎) or On Legal theory of Muslim Jurisprudence is a 12th-century treatise written by Abū Ḥāmid Muḥammad ibn Muḥammad al-Ghazali(Q.S).[1] While Ghazali was deeply involved in Tasawwuf and Kalam, Islamic Law and Jurisprudence formed the core of his concerns.[2][3]