Ezekiel 33:27-33

You shall say this to them, ‘Thus says the Lord GOD, “As I live, those who are in the ruins certainly will fall by the sword, and I will give whoever is in the open field to the [predatory] animals to be devoured, and those who are in strongholds and in caves will die of virulent diseases. And I will make the land [of Israel] a desolation and a ruin, and her pride in her power will be brought to an end; and the mountains of Israel will be so deserted that no one will pass through. Then they will know [without any doubt] that I am the LORD, when I make the land a desolation and a ruin because of all the atrocities which they have committed.” ’ “But as for you, son of man, your people who talk about you by the walls and in the doorways of the houses say one to another, every one to his brother, ‘Come now and hear what the message is that comes from the LORD.’ They come to you as people come, and they sit before you as My people, and they hear your words, but they do not practice them; for with their mouth they express loving devotion, but their heart goes after their (unlawful) gain. Behold, you are to them like a love song by one who has a pleasant voice and plays well on a stringed instrument [merely to entertain them]; for they hear your words but do not practice them. So when it comes to pass—as it most certainly will—then they will know [without any doubt] that a prophet has been among them.”