Hebrews 13:2 says some who showed hospitality to strangers unknowingly entertained whom?

Answer: Angels

"Do not neglect to show hospitality to strangers, for by so doing some people have entertained angels without knowing it."

“Do not neglect to show hospitality to strangers, for by so doing some people have entertained angels without knowing it.”— Hebrews 13:2 (BSB)