THE HEIR OF THE PROMISE
“The appearing of the Lord as a man or as an Angel of the covenant anticipates the Incarnation. The term ‘theophany’ describes such appearances of the Lord. God told the nation of Israel in the wilderness that He was sending His Angel before them to keep on the way, and to bring them to the Promised Land. ‘Pay attention to him and listen to what he says. Do not rebel against him; he will not forgive your rebellion, since my Name is in him’ (Ex. 23:21). As the possessor of the divine Name, the Angel is the representative of God’s presence, the form in which God Himself appears-distinct from the Lord, yet identified with Him.” (Edmund Clowney)
For more on the subject, please visit the Biblical Theology page.