Fiqh-us-Sunnah Volume 3, Zakaat and Fasting, Fiqh 3.093.

Section : Wayfarere (wab nisabil), recipients of sadaqah.

In the case of the wayfarer cut off from family and relatives, as if travelling were his household, consideration requires kindness for him as well. Thus, to sympathize with him and help him in his travels is, within the meaning of Islamic law, an encouragement which invites one to journey throughout the earth.