During journey through the desert two friends had an argument and one slapped the other.
The one hurt wrote in the sand:
TODAY MY BEST FRIEND SLAPPED ME IN THE FACE
Later they reached an oasis and decided to take bath. One who had been slapped got stuck in the mire and started drowning but the other saved him. Then he wrote on a stone:
TODAY MY BEST FRIEND SAVED MY LIFE.
The friend who had slapped and saved him asked, “After I hurt you, you wrote in the sand and now, you write on a stone, why?”
The other replied, “When someone hurts us we should write it in sand where winds of forgiveness can erase it away. But, when someone does something good for us, we must engrave it in stone where no wind can ever erase it.”