Luqman, who was wise person, served an officer when he was a young boy.
One day, his master: ''Slaughter one of the sheep and roast the best part of its meat for me.''
Luqman obeyed his order and roasted the tongue of the sheep for his master.
The next day, the master called Luqman and said: ''Roast the worst of a sheep today.
Luqman again roasted the tongue of the sheep for his master.
When the officer sat down to eat, he was startled to see the roasted tongue again. He felt curious and wanted to know the reason. Luqman
Luqman told him saying of Prophet Muhammad (Peace be upon him), ''If the tongue is truthful and honest, then it is the best part of the body. But when a tongue lies and utters dishonest words, then it is the worst part of the body.''