Chapter on Itikaf and What Fasting Is Obligatory in It

Muhammad ibn Yaqub narrated from Ahmad ibn Muhammad, from Ibn Mahbub, from Abu Ayyub, from Abu Basir, from Abu Abdillah عليه السلام, peace be upon him: Imam عليه السلام said: “Seclusion (itikaf) is not less than three days, and whoever observes itikaf must fast. And it is appropriate for the one observing itikaf, when he observes itikaf, to stipulate a condition, just as the one who enters ihram stipulates a condition.”