Thief Can't Question A Robber

Once a wolf was roaming about in a field of grass where a flock of sheep came grazing every day. He was hiding behind a bush. Getting a chance, he carried away a lamb to eat it at a safe place. Unfortunately, a lion came there, snatched the lamb, and went to his den to eat it at leisure. 

When the lion had walked just a few steps away, the wolf said, "It is down daylight robbery- so unjust for a lion to snatch my morsel from me. It is below his dignity."

Hearing the wolf's grumble, the lion laughed and replied, "A thief is questioning a robber- how strange! Did you get this lamb as a gift from a friend? You stole it out of a flock. Was that fair?"

A sin is a sin- whether big or small.