Messengers were often used to announce important messages. The fact that this messenger is called the “messenger of the covenant” would indicate that this messenger would convey an important message about the covenant. What was that message? We are not told in this text. But it is not difficult to deduce, considering all that God had promised concerning the covenant. God had promised to “make a new covenant” with his people, a “better covenant” (Jeremiah 31:31–32; Isaiah 55:3; Isaiah 61:8; Ezekiel 16:62; Ezekiel 37:26). The mere mention of the coming of “the messenger of the covenant” would arouse excitement and hope for the fulfilment of these promises. The fact that the people “delighted” in this messenger points to the fact that the long-awaited Messiah was going to come, to inaugurate the new covenant.
1 “Behold, I send my messenger, and he will prepare the way before me. And the Lord whom you seek will suddenly come to his temple; and the messenger of the covenant in whom you delight, behold, he is coming, says the LORD of hosts.