In order to escape King Saul's jealous, murderous rage, David, though innocent, had to run for his life. He soon found himself a wanderer, a nomad, looking for any safe place that might provide protection for a little while. During that time, he found a cave to live in, and he wrote two psalms while living there. Psalm 57 is very hopeful. Psalm 142 is discouraged, fighting for hope.