Sentence:  And indeed I blamed myself and sore repented me of having taken compassion on him and continued in this condition, suffering fatigue not to be described, till I said to myself, "I wrought him a <WSD>weal</WSD> and he requited me with my ill; by Allah, never more will I do any man a service so long as I live!" 
Meaning of the word marked with <WSD> tags:  Boon, benefit.