My father رحمه الله narrated to us, saying that Muḥammad b. Yaḥyā al-ʿAṭṭār narrated to him among others, from Muḥammad b. Aḥmad, from Ibrāhīm b. Hāshim, from Ḥamza b. Yaʿlī, from Muḥammad b. al-Ḥusayn b. Abī Khālid, who raised it up to Abī ʿAbd Allāh عليه السلام [the manuscripts differ], who said: “When you verify that the crescent moon of the month of Rajab has appeared, start counting for fifty-nine days, then fast on the sixtieth.”