Okay, I finally have time to delve a little deeper into this "capitalized" angel of Ex 23:20. God also mentions something similar in 32:34, and 33:2 about sending an angel before them. Remember, also, that an angel accompanied the children of Israel as they were leaving Egypt and approaching the Red Sea (14:19).
How do we know that this angel which God is sending before the children of Israel is JUST an angel and not something more, such as what Trinitarian scholars assert: the "Angel" was actually a pre-incarnate manifestation of the second person of the Trinity- God The Son? (BTW, the term "Son of God" is in the Bible; the term "God The Son" is not. The first refers to God manifested in the flesh. The second refers to the Trinitarian "second person".)
Because we know from what the writer of the book of Hebrews had to say about all this. The book of Hebrews is a formal treatise on how Jesus Christ, the Son of God, is better than anything in the Old Covenant, and anything attached to or surrounding the Old Covenant. And the writer begins by showing how the Son is a superior revelation of the Word of God than what the prophets of old were (1:1-2). He then proceeds through the rest of the chapter to demonstrate how the Son is superior to the angelic order. He concludes at the beginning of chapter 2 with this:
"Therefore we ought to give the more earnest heed to the things which we have heard, lest at any time we should let them slip. For if the word spoken by angels was stedfast, and every transgression and disobedience received a just recompence of reward; How shall we escape, if we neglect so great salvation; which at the first began to be spoken by the Lord, and was confirmed unto us by them that heard him;" (2:1-3).
What is this "word spoken by angels"? It is none other than the giving of the Law. Here, the writer is contrasting the Gospel message spoken by the Son and His apostles vs. the message of the Law. And who spoke the message of the Law? According to the writer here..."angels"! We would think he should have said "the word spoken by Moses". Which, of course, it was. But Moses apparently received it "spoken by angels".
At this point, I could easily say, "Hey, wait a minute! I thought Moses received the Law directly from God Himself!" Yes, he did, but via the agency of angels. What was it that God told Moses back in Ex. 23? He said:
"Beware of him [the angel], and OBEY HIS VOICE, provoke him not; for he will not pardon your transgressions: for my name is in him. But if thou shalt indeed OBEY HIS VOICE, and do all that I speak; then I will be an enemy unto thine enemies, and an adversary unto thine adversaries." (vs. 21-22, emphasis mine)
So, where is all this talking that this angel was supposed to have done during their journey in the wilderness? All we're ever aware of is where God talked to Moses (and others). Exactly! The focus is always on God, and rightly so! All we're told by Moses in Ex. 23, and all we're told by the Hebrews writer in chapter 2, is that somehow angels were involved in the transmission of the Law to Moses.
Now, if the angel of Ex. 23 had really been "God The Son" and not an angel, the place in Scripture were this would have been disclosed is precisely in Hebrews chapters 1 & 2! The writer, in contrasting the superiority of the Son to angels, would have told us very clearly that it was really the Son, and not angels, which led Moses and Israel beginning in Ex. 23. But he does not. In fact, he says just the opposite. Where do we begin to hear from the Son of God? "In these last days..." (1:2). And what message did the Son bring? The message of the Gospel, along with His apostles (2:1-3). And this is in direct contrast to the "word spoken by angels".
In conclusion, who is this angel spoken of by God in Ex. 23? Just an angel! How do we know? Because the writer of Hebrews clearly tells us. When do we finally hear from the Son of God? "In these last days"!
Well, we ran out of time last night in Bible Study to discuss this angel, so I'll do it here. The short answer: the KJV translators capitalized the word angel in Ex. 23:20 because they believed it wasn't really an angel at all, but the second divine person of the Trinity- God The Son.