In the Old Testament, when the article “the” is used with this phrase Angel of the LORD, it is specifying a unique being, separate from the other angels. In Judges 2:1 we read, “And an angel of the LORD came up from Gilgal to Bochim, and said, I made you to go up out of Egypt, and have brought you unto the land which I sware unto your fathers; and I said, I will never break my covenant with you.”
It is difficult to ascertain of whom the writer is speaking when he refers to “an angel of the Lord.” The word “angel” literally means “messenger.” The term “messenger of the Lord” may refer to a prophet whom God used to give His message to Israel (Haggai 1:13), but it may also refer to the Lord Himself, who is sometimes referred to by this title (Ex. 23:20, 23; 33:2). The fact that the message is not introduced with a “Thus saith the Lord,” which was the custom of later prophets, suggests that the speaker was the Lord Himself. The use of the first person also supports the latter view.
The following verses show that the angel of the Lord speaks as God, identifies Himself with God, and exercises the responsibilities of God (Genesis 16:7-12; 21:17-18; 22:11-18; Exodus 3:2; Judges 5:23; 6:11-24; 13:3-22; 2 Samuel 24:16; Zechariah 1:12; 3:1; 12:8). In some instances the angel of the Lord was a messenger from God. And in other references to this phrase, those who saw the angel of the Lord realized that they have “seen the Lord.” Therefore, it can be seen that the angel of the Lord is an appearance of God in physical form.
In the New Testament, we don’t find the phrase the angel of the Lord. So we can conclude that the angel of the Lord appearances were manifestations of Jesus before His incarnation. Jesus declared Himself to be existent “before Abraham” (John 8:58).
In His service,