He—may Allah have mercy on him—was asked:

“A traveler who fasts during Ramadan is reproached, accused of ignorance, and told that not fasting is better. What travel distance permits shortening the prayers? If someone sets out on a journey during the day, may he break his fast? May travelers such as those who hire out mounts, merchants, camel drivers, sailors, and passengers at sea refrain from fasting? What is the difference between journeys undertaken in obedience to Allah and those undertaken for a sinful purpose?”

He replied:

Praise be to Allah. Muslims agree that a traveler may refrain from fasting, whether traveling for Hajj, jihad, trade, or any similar purpose that Allah and His Messenger do not disapprove of. As for journeys undertaken for a sinful purpose, such as traveling to commit highway robbery and the like, there are two well-known scholarly opinions, just as there are concerning shortening the prayers on such journeys. As for a journey on which prayers may be shortened, it is permissible to refrain from fasting and make up the missed days