'Angel of the Lord' in the Bible

And, while thinking of these things, behold, an angel of the Lord appeared to him in a dream, saying, "Joseph, son of David, fear not to take to yourself Mary your wife; for that which was begotten in her is of the Holy Spirit.

And Joseph, arising from sleep, did as the angel of the Lord directed him, and took to himself his wife;

And, they having departed, behold, an angel of the Lord appears to Joseph in a dream, saying, "Having risen, take the Child and His mother, and flee into Egypt, and be there till I speak to you; for Herod is about to seek the Child to destroy Him."

And, Herod having died, behold, an angel of the Lord appears to Joseph in a dream in Egypt, saying,

And, behold, there occurred a great commotion; for an angel of the Lord, descending out of Heaven, and coming near, rolled away the stone, and was sitting upon it.