From Sahih Bukhari (Hadith 2892):
Narrated Sahl bin Sa`d As-Sa'idi:Allah's Messenger (ﷺ) said, "To guard Muslims from infidels in Allah's Cause for one day is better than the world and whatever is on its surface, and a place in Paradise as small as that occupied by the whip of one of you is better than the world and whatever is on its surface; and a morning's or an evening's journey which a slave (person) travels in Allah's Cause is better than the world and whatever is on its surface
Reference: Bukhari 2892