Answered by Shaykh Mazhar Mahmood
Is it permissible for a man to travel long distances with his mother in law?
It is permissible for a man to travel with his mother in law for any amount of time or distance. Islam encourages a closely knit family lifestyle, especially with individuals who have become part of the family through the blessed covenant of marriage.
In Islāmic ethics and principles, an individual’s mother in law takes a position parallel to one’s biological mother. Just as it is forbidden and unnatural to marry one’s own mother; the same applies in context of one’s mother in law. Similarly, just as a man is allowed to travel with his biological mother; he is allowed to travel with his mother in law.
In the verse of the Qur’ān that lists relatives who one cannot marry, Allāh Almighty says,
“… and the mothers of your wives…” (Qur’ān: 4: 23)
Based on the above-mentioned verse, Muslim jurists conclude that the son in law constitutes the definition of a maḥram for his mother in law. Therefore, it is completely legitimate for a man to travel with his mother in law, as long as he does not strongly fear any form of ethical or moral corruption in his travel. (See: Radd al Muḥtār, 2: 160)
Allāh Almighty Knows Best