What did the Prophet Muhammad (peace be upon him) say regarding fasting on 'Id day?
 Narrated Ziyad bin Jubair:                     A man went to Ibn `Umar I. and said, "A man vowed to fast one day (the sub-narrator thinks that he said that the day was Monday), and that day happened to be `Id day." Ibn `Umar said, "Allah orders vows to be fulfilled and the Prophet forbade the fasting on this day (i.e. Id).