My father رضي الله عنه narrated to us, from Saʿd b. ʿAbd Allāh, from Yaʿqūb b. Yazīd, from Ḥammād b. ʿĪsā, from Ḥarīz b. ʿAbd Allāh, from Zurāra b. Aʿyan, from Abī Jaʿfar Muḥammad (al-Bāqir, عليه السلام), who said: “Islam is built on five things—upon prayer, the obligatory alms-tax, fasting, the pilgrimage (to the Kaaba in Mecca), and Divine authority, and the Messenger of Allāh صلى الله عليه وعلى آله has said: “Fasting is a shield against the Fire.”