vow, according to the four imams and others. The three mosques, however, are different: if someone vows to travel to the Sacred Mosque for Hajj or ‘umrah, he must do so by agreement of the imams. If he vows to travel to either of the other two mosques, he must undertake the journey according to most of them, including Mālik, Ahmad, and al-Shāfi‘ī according to the stronger of his two opinions. This is based on the words of the Prophet, may Allah bless him and grant him peace:

“Whoever vows to obey Allah, let him obey Him; and whoever vows to disobey Allah, let him not disobey Him.”

Narrated by al-Bukhārī.

A vow must be fulfilled only when it concerns an act of obedience, such as a vow to pray, fast, observe a devotional retreat, give charity for Allah’s sake, or perform Hajj. Thus, a vow to travel to somewhere other than the three mosques does not make that journey obligatory, because it is not an act of obedience. The Prophet, may Allah bless him and grant him peace, said:

“Journeys should not be undertaken except to three mosques.”

He thus prohibited travelling to any mosque other than the three mosques, so travelling to places other than mosques is even more deserving of prohibition. Worship in mosques is undoubtedly superior to worship in places that are neither mosques nor homes. Moreover, it is authentically reported that he, may Allah bless him and grant him peace, said:

“The places most beloved to Allah are the mosques.”

Furthermore, his words, “Journeys should not be undertaken except to three mosques,” encompass the prohibition of travelling to any place sought out for its own sake. This differs from travelling for trade, seeking knowledge, and similar purposes, since such journeys are undertaken to obtain what is needed, wherever it may be found. The same applies to travelling to visit a brother in faith: the person himself is the purpose of the journey, wherever he may be.

Some later scholars have stated that there is no harm in travelling