'Angel' in the Bible

But the angel of Yahweh said to Elijah the Tishbite, "Arise, go up to meet the messengers of the king of Samaria, and tell them, 'Is it because there is no God in Israel, that you go to inquire of Baal Zebub, the god of Ekron?

The angel of Yahweh said to Elijah, "Go down with him. Don't be afraid of him." He arose, and went down with him to the king.

It happened that night, that the angel of Yahweh went out, and struck one hundred eighty-five thousand in the camp of the Assyrians. When men arose early in the morning, behold, these were all dead bodies.