Charles Ellicott Commentary Acts 12:7

"And behold, an angel of the Lord stood by him, and a light shined in the cell: and he smote Peter on the side, and awoke him, saying, Rise up quickly. And his chains fell off from his hands." — Acts 12:7 (ASV)

The angel of the Lord came upon him.—The phrase is identical with that of Luke 2:9. The absence of the article in the Greek leaves it open to render it either as “the angel” or “an angel.” The “light” in this instance corresponds to the “glory of the Lord” in that.

In the prison.—Literally, in the dwelling, or chamber. The term appears to be used as a euphemism for “prison.”