PONY BOY receives a letter from whom the outsider?

In "The Outsiders" by S.E. Hinton, Ponyboy receives a letter from Johnny Cade while he is in the hospital. Johnny writes to Ponyboy encouraging him to stay golden and to appreciate the beauty in life, expressing his thoughts on the importance of dreams and innocence. The letter serves as a poignant reminder of their friendship and the struggles they face in their harsh environment. It highlights Johnny's wisdom and vulnerability, leaving a lasting impact on Ponyboy.