David is marooned for over four days on a rocky isle
he had come to land upon. Countless times David
feared dying miserably alone. He felt numb from the
chilly rains and nauseated from his diet of raw
shellfish. Yet David only breaks down and despairs
once. What nurtured his hope during those many
lonely hours of wretchedness? Please be specific in
your response.

I have been looking for this for 3 hours. The book is Kidnapped by robert louis