When I bring the sword against a land, and the people of the land choose one of their men, and make him their watchman, and he sees the sword coming against the land and blows the trumpet to warn the people, then if anyone hears the trumpet, but does not take the warning and the sword comes and takes his life, his blood will be on his own head. Since he heard the sound of the trumpet but did not take warning, his blood will be on his own head. If he had taken warning he would have saved himself.
But if the watchman sees the sword coming and does not blow the trumpet to warn the people and the sword comes and takes the life of one of them, that man will be taken away because of his sin, but I will hold the watchman accountable for his blood. (Ezek. 33:1-6)