Ruling 1685 — Fasting (Ṣawm)

If an assigned [i.e. time-specific] fast – other than the fast of the month of Ramadan – is obligatory for a person, then in the event that it has become obligatory because he has been hired by someone to fast and suchlike, or it is the third fast of the days of spiritual retreat (iʿtikāf),[2] he cannot travel on that day; and if he is on a journey and it is possible, he must make an intention to stay in a place for ten days and fast on that day. However, if the fast of that day has become obligatory on account of a vow, the apparent (ẓāhir)[3] ruling is that travelling is permitted on that day and it is not obligatory to make an intention to stay, although it is better not to travel if one is not obliged to, and if he is on a journey, it is better to make an intention to stay. However, if it has become obligatory on account of an oath (qasam) or a covenant (ʿahd), then based on obligatory precaution, one must not travel, and if he was on a journey, he must make an intention to stay.