"Contemplating is receiving." (St. John of the Cross) What we receive in prayer is the Spirit, who makes all creation new, moment by moment. It is the Spirit who rebirths us within the caves of our hearts. The case is a metaphor for this silent withdrawal, this going away to be alone, to listen, to gestate the Spirit, to rebirth ourselves. The reborn self is the child of wisdom born in solitude.
Sometimes in your life you will go on a journey. It will be the longest journey you have ever taken. It is the journey to find yourself.