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When you see the word LORD in capital letters it almost always refers to the "Memorial Name" of God, YHWH, or, "YAHWEH". It is used in God's work with His people and the name is given to the one who is entrusted with the overall well-being of His "sons and daughters".
So, we see the NAME was borne by an angel, possibly Gabriel or Michael, who excercised God's will with Israel. See Exodus 23:20-23. Now that position is occupied by the Lord Jesus Christ. See John 1:14; Philippians 2:5-11.
I hope you have found this helpful.