“Once upon a time, there were two friends who were walking through the desert, having lost their camels and having spent days without eating anything. One day, an argument arose between them in which one of the two rebuked the other for having chosen the wrong route (although the decision had been joint) and in a fit of anger slapped him. 

Later both arrived at an oasis, in which they decided to bathe. They were in it when the previously attacked began to drown, to which the other responded by rescuing him. The young man thanked him for his help and later, with a knife, wrote on a stone that his best friend had saved his life.

The first, curious, asked his partner why when he had hit him he had written in the sand and now he was doing it on a stone. The second smiled at him and replied that when someone did something bad to him he would try to write it on the sand so that the mark would be erased by the wind, while when someone did something good he preferred to leave it engraved in stone, where it will remain forever. " 

This beautiful legend of Arab origin tells us that what we must value and keep fresh in our memory are the good things that others do, while the marks that bad things leave us we must try to blur and forgive over time.