Angel Of The Lord
Baker's Evangelical Dictionary of Biblical Theology 
(Heb. mal'ak yehwah) . Supernatural being who bears a message on behalf of God. In many passages in the Old Testament, the angel of the Lord is identified with God, while in other instances a distinction is made between the Lord and the angel. In general, however, the terms "the angel of the Lord, " "the Lord, " and "God" are interchangeable.
The angel of the Lord is the messenger of both good and evil. He comes to Hagar after she has fled from the abusive Sarai ( Genesis 16:7-14 ) to assure her that God has heard about her misery and that her descendants will be too numerous to count. She names him "You are the God who sees me" (v. 13). The angel of the Lord pronounces a curse on the people of Meroz, because they refused to come to the help of the Lord ( Judges 5:23 ).
The angel of the Lord both commissions and commends God's servants. The commander of the Lord's army commissions Joshua to undertake the Lord's battles for Canaan, just as Moses had been commissioned to confront Pharaoh ( Joshua 5:13-15; cf. Exodus 3:5 ). The angel of the Lord appears to Abraham. He stops Abraham from sacrificing Isaac and commends him because he has not withheld his only son from God ( Genesis 22:11-18 ). Abraham identifies the angel as God, calling the place "The Lord Will Provide."
The angel of the Lord carries out a ministry of reconciliation. He asks how long God will withhold mercy from Jerusalem and Judah ( Zechariah 1:12 ).
The connection between the angel of the Lord and the preincarnate appearance of the Messiah cannot be denied. Manoah meets the angel of the Lord, and declares that he has seen God. The angel accepts worship from Manoah and his wife as no mere angel, and refers to himself as "Wonderful, " the same term applied to the coming deliverer in Isaiah 9:6 ( Judges 13:9-22 ). The functions of the angel of the Lord in the Old Testament prefigure the reconciling ministry of Jesus. In the New Testament, there is no mention of the angel of the Lord; the Messiah himself is this person.
See also Theophany
Bibliography . A. Bowling, TWOT, 1:464-65; G. B. Funderburk, ZPEB, 1:160-66; J. B. Payne, Theology of the Older Testament .
American Tract Society Bible Dictionary 
The Angel Jehovah, the usual title of Christ in the Old Testament. Compare Genesis 16:7-13; 22:11-18; 31:11-13; 32:24-30; Exodus 3:2-6,14; 23:20; Judges 2:1-23; 13:16-22; Acts 7:30-38 . Christ thus appears in the Patriarchal, the Mosaic, and the Christian dispensation as the same Jehovah, revealing the Father to men, and carrying forward the same great plan for the redemption of his people, Isaiah 63:9 .
Smith's Bible Dictionary 
Angel of the Lord. Genesis 16:7, etc. (The special form in which God manifested himself to man, and hence, Christ's visible form before the incarnation. Compare Acts 7:30-38, with the corresponding Old Testament history; and Genesis 18:1; Genesis 18:13-14; Genesis 18:33 and Genesis 19:1.
Fausset's Bible Dictionary 
(See Angels .)