Abu Huraira reported, The Prophet said, The believer will wear down his devils by obeying God, just as you wear down your camel by travelling.
-Hadith of Ahmad ibn Hanbal (780-855)
The verb translated here as “wear down”, Nadā, in Form I means “to undress” and in Form IV, as used by Ahmad ibn Hanbal, means “to wear out (a riding animal)”. When in the saddle ten hours a day on the Darb, feeling in my seat every jolting step my camel took, I never thought what I really felt wearing out were my devils, not my derrière.