Sheep's Tongue

A king once asked his servant to bring him the best part of a sheep. The servant went to the market and returned with a sheep’s tongue. The next time, the king asked him to bring the worst part of the sheep. Again the servant brought the sheep’s tongue.
On enquiry, he stated that the tongue was the best part of a person when it was used to speak good things, heal rifts and make people happy. And the tongue was the worst part as well if it was used in sowing discord, speaking evil and hurting people.

Wounds inflicted with the sword can heal,
But wounds inflicted with the tongue cannot be healed. (Arabic Saying)