The first metaphor is that of a drowning person. He can’t swim, and he is going under. Even his head is submerged below the waves, and the only thing left above the surface of the water is his hand. He cannot possibly save himself from drowning unless someone throws him a life preserver. Someone on shore then throws that life preserver exactly where the man needs to have it thrown, right up against his hand. The person on the shore has done everything that he can do to save the drowning man, but the drowning man must either grab hold of the life preserver or let it pass by.
