We can use as evidence the fact that Kino keeps and takes care of the pearl that he believes will allow him to provide a better life for his family.
Explanation:
"The pearl" is a book that tells the story of Kino, a humble Amerindian who doesn't have enough money to take care of his family and provide a better life for them. One day his son becomes ill and the doctor refuses to help him, because Kino has no money to pay for any treatment.
Desolate, Kino ends up finding a grand and beautiful stone. He believes that the sale of this stone will allow him to have money to take care of his family and that is why he is very careful with the pearl and the guard and protects it with great zeal.
