Ironically- and apologies for the side note– angels are indeed an Old Testament and Midrashic (i.e. Jewish) concept. They have many names/nomenclatures depending on their functions- seraphim, melachim, etc. However, because of various prohibitions on artworks showing God, the human form, holy beings with a physical manifestation, etc. writings about angels in Jewish literary works is prolific- artistic depictions not so much. The famous paintings showing angels appearing in various events in the Old Testament (to Hagar, to Abraham, Jacob’s ladder, etc.) are mainly (but not exclusively) works of Christian artists.
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