Ezekiel 33:2-4

2“Son of man, speak to your people and say to them: ‘When I bring the sword against a land, and the people of the land choose one of their men and make him their watchman, 3and he sees the sword coming against the land and blows the trumpet to warn the people, 4then if anyone hears the trumpet but does not heed the warning and the sword comes and takes their life, their blood will be on their own head.