It was the kingship of Yahweh that had constituted Israel, and Israel would survive only as that imperium continued, overarching and overruling the power of human kings.1 So when the prophets said, «Thus says the LORD,» they were representing the ancient, original, final, and legitimate authority in Israel. (religion-online.org)
In Jeremiah's time the people's understanding of kingship was tainted by human kings who had led them to the point of imminent destruction and deportation. (religion-online.org)
Both the Isaiah and Ezekiel passage are talking about human kings — not necessarily Satan. (redeeminggod.com)