حنين بن إسحاق
The "Duties of the Heart" is divided into ten sections termed "gates" () corresponding to the ten fundamental principles which, according to Bahya's view, constitute human spiritual life. This treatise on the inner spiritual life makes numerous references to both Biblical and Talmudic texts. It also draws on the Sufi influences of al-Andalus and also on the Greco-Roman Classics as translated by the school of Hunayn ibn Ishaq.