how did aram convince himself to ride the house

In the story "The summer of the Beautiful White Horse" Aram is shocked to see his older cousin Mourad riding on the white horse. He is amazed on this as he knew that their family could not afford the horse and questions Mourad if he had stolen the horse. On this Mourad said that this was not stealing. He had only taken the horse without informing the owner. If they would have sold this horse for money then it would have been stealing. Aram gets convinced on this and believes that they would return the horse and have taken it only for some time.