'Angel of the Lord' in the Bible

And the angel of the LORD found her by a fountain of water in the wilderness, by the fountain in the way to Shur.

And the angel of the LORD said unto her, Return to thy mistress, and submit thyself under her hands.

And the angel of the LORD said unto her, I will multiply thy seed exceedingly, that it shall not be numbered for multitude.

And the angel of the LORD said unto her, Behold, thou art with child, and shalt bear a son, and shalt call his name Ishmael; because the LORD hath heard thy affliction.

And the angel of the LORD called unto him out of heaven, and said, Abraham, Abraham: and he said, Here am I.

And the angel of the LORD called unto Abraham out of heaven the second time,