John Chrysostom, on Heb 13:2

“And hospitality do not forget; for by this some, being not aware of it, have entertained angels.”

“He did not say, "Be hospitable," as if they were not, but, "Be not forgetful of hospitality," for this was likely to happen owing to their afflictions. Therefore (he says) "some have entertained angels unawares." Seest thou how great was the honor, how great the gain! What is "unawares"? They entertained them without knowing it. Therefore the reward also was great, because he entertained them, not knowing that they were Angels. For if he had known it, it would have been nothing wonderful. Some say that he here alludes to Lot also.”

Imported from an open dataset — not yet checked against the printed edition.