Story about Friendship!

This is a story that I understand about Friendship I would Like to share it with you guys.

Once two friends argued, and one of them slapped another. This man felt a pain, but telling nothing and wrote on the sand: Today my best friend slapped me.They continued walking and found an oasis, in which wellspring decided to swim. The one who was slapped, started to sink, but his friend saved him. When he regained consciousness, wrote on the stone: "Today my best friend saved my life."Another friend, who slapped and saved his friend’s life, of 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.