What is the ruling regarding someone who vowed to fast every Monday and Thursday for the rest of his life, but then one of these days coincided with the days of Tashreeq, so he broke his fast? Should he make up for it or is it waived for him?

Fulfilling a vow is a religious obligation. So, whoever vows an act of obedience to Allah must fulfill it, based on the Prophet's (peace be upon him) saying: "Whoever vows to obey Allah, let him obey Him; and whoever vows to disobey Him, let him not disobey Him."

If the vow coincides with days on which fasting is not prescribed, such as the Days of Tashreeq, scholars have differed regarding its ruling: - Hanbali jurists are of the view that both a make-up fast and expiation are obligatory due to the expiration of the vow's designated time. - Others are of the view that neither a make-up fast nor expiation is due.