Two good friends had a quarrel one day, and one of them slapped another. The man felt pain, but said nothing and wrote on the sand: “Today my best friend slapped me.” Two friends continued walking and found an oasis. They decided to swim in a wellspring and suddenly the one who was slapped, started to sink, but his friend saved him. When he regained consciousness, he wrote on the stone: “Today my best friend saved my life.” The other friend, who slapped and saved his friend’s life, asked him: – When I hurt you, you wrote on the sand and now you are writing on the stone. Why? His friend said: – When someone hurts us, we should write it on the sand, so that the wind could erase it. But when someone does something good for us, we must engrave it on the stone, so that the wind could not erase it.