Who is the most sinful and most sinless person in the world

In the time of Moses, one of the men asked Moses (as):
Who is the most sinful man in the world? "
Moses (pbuh) asked after Allah (cc) that he had worshiped on Mount Tur:
'' Who is the most sinful servant in your servants? ''
Allah (cc):
'' -Yes Moses, after you leave from here a little later, a boy and his father will go to sleep.
That man is the most sinful man in the world. "
And so a man and a child pass by and he sees the sinner. A certain time passes after
Again asking to Moses (as):
'' Who is the most sinless man in the world? ''
They say. Moses (as) again refers to Allah (cc):
'' - '' Rabbi said, 'who is the most sinless covenant in the world?'
Allah is the eternal and celle:
'' - Moses said, 'when you leave here, a child and his father will pass by, and that man is the most sinless man in the world!'
Moses (as) looks at the same man as the man of yesterday
Hz Moses:
How could he be the most sinless man today while he was the most sinful man in the world yesterday?
Allah (cc) says:
'' -Yes Moses left you and this child and his father went to the sea. The child asked his father:
-What is bigger than these sand? "
Father:
'' My son has a bigger sea wave than these sand, they have foam. '' The child again:
'' - Daddy, what's so big about this sea? ''
'' - says the sins of the father. '' This is the child, he asks:
'' -Your father, what is greater than your sins? '' The man says in response:
'' God has greater mercy than the sins of the Father, my son. '' Allah (cc) to Moses (as):
'' Job, 'Moses knew me, who had a greater mercy than his sins. I forgave him ...