[Reason and Reward]
Usul al-Kafi, book of reason and ignorance, pg 28
‘Ali ibn Muhammad ibn ‘Abdillah al-Ibrah narrates from ibn Is'haq al-Ahmar from Muhammad ibn Sulayman al-Daylami from his father, who said :
I told Abu ‘Abdillah [a], ‘Such and such a person is praiseworthy for his devotion and religious practice.’
The Imam inquired, ‘How is his reason?’
I replied, ‘I know nothing about his reason.’
Upon this, the Imam explained,
‘The Divine reward is in relation to one's reason.
There was a person from Bani Israil who used to worship God devotedly in an island full of lush green and clear water. An angel happened to watch that person, and asked God, ‘Kindly show me the rewards meant for that person.’
When the angel was shown the rewards by God, they appeared to be very little to him. Upon this God suggested to him to go and stay with that person (for some time).
The angel appeared before that man in human guise. The man asked the angel, ‘Who are you?’ The angel replied, ‘I am also one of the devotees of God and I have heard about this place and your worship in it. Therefore, I have come to you so that I can also pray to Almighty God with you.’
So the angel stayed with him for a day. When it was morning, the angel remarked, ‘This is a pleasant place; no place could be better than this for worshipping God.’
Then the devotee-replied, ‘There is only one defect in this place.’
The angel asked what it was and the man replied, ‘My Lord has no animal. If He had a donkey, we could pasture it in this place, for the grass is going waste.’
The angel remarked, ‘Your Lord has no donkey?’
The man further said, ‘If He (Allah) had a donkey such a quality of grass would not be wasted.’
Then Almighty God revealed to the angel, ‘My rewards are in relation to a person's reason.’"