That Christ is at once Angel and God
In Genesis, to Abraham: “And the Angel of the Lord called him from heaven, and said unto him, Abraham, Abraham! And he said, Here am I. And He said, Lay not your hand upon the lad, nor do anything unto him. For now I know that you fear your God, and hast not spared your son, your beloved son, for my sake.” Also in the same place, to Jacob: “And the Angel of the Lord spoke unto me in dreams, I am God, whom you saw in the place of God where you anointed me a pillar of stone, and vowed to me a vow.” Also in Exodus: “But God went before them by day indeed in a pillar of cloud, to show them the way; and by night in a pillar of fire.” And afterwards, in the same place: “And the Angel of God moved forward, which went before the army of the children of Israel.” Also in the same place: “Lo, I send my Angel before your face, to keep you in the way, that He may lead you into the land which I have prepared for you.
Observe Him, and obey Him, and be not disobedient to Him, and He will not be wanting to you. For my Name is in Him.” Whence He Himself says in the Gospel: “I came in the name of my Father, and you received me not. When another shall come in his own name, him you will receive.” And again in the cxviith Psalm: “Blessed is He who comes in the name of the Lord.” Also in Malachi: “My covenant of life and peace was with Levi; and I gave him fear, that he should fear me, that he should go from the face of my name.
The law of truth was in his mouth, and unrighteousness was not found in his lips. In the peace of the tongue correcting, he walked with us, and turned many away from unrighteousness. Because the lips of the priests shall keep knowledge, and they shall seek the law at His mouth; for He is the Angel of the Almighty.”
Source: The Treatises of Cyprian (New Advent)