Anger
There was once a young boy who had problem controlling his temper.
When he became angry, he would just say anything that came to his mind and hurt people.
So his father gave him a bag of nails and a hammer and said, Every time you get angry, hammer one nail into the fence in our backyard.
The first few days the boy hammered so many nails that he emptied half the bag.
Over the weeks, the number of nails he hammered to the fence reduced and gradually, his temper was much in control.
Then came a day when he didn't lose his temper at all.
His father asked him to remove one nail each day that he manages not to lose temper.
Finally, on the day the child was removing the last nail, his father says, You have done well, boy. But did you see all the holes in the wall?
The fence is never going to the same, even after repainting.
Likewise, when you say mean things in anger, you will leave a scar in the person's mind, as the nails did to the fence.
Anger is dangerous weapon like a knife. When you put a knife in a man and draw it out, the wound heals but the scar remains.