'Angel of the Lord' in the Bible

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

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

And the angel of the LORD said unto her, I will multiply your descendants exceedingly, that they shall not be numbered for multitude.

And the angel of the LORD said unto her, Behold, you are with child, and shall bear a son, and shall call his name Ishmael; because the LORD has heard your 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,