'Messenger' in the Bible

For the lips of [the] priest should guard knowledge, and they should seek instruction from his mouth, for he [is] the messenger of Yahweh of hosts.

"Look! I [am] going to send my messenger, and he will prepare [the] way {before me}. And the Lord whom you [are] seeking will come suddenly to his temple, and the messenger of the covenant, [in] whom you [are] taking pleasure--look!--[he is] about to come," says Yahweh of hosts.