Acts 14:12. Mythology represented Mercurius as having once visited Phrygia with Jupiter his father, and having been refused hospitality by all except Baucis and Philemon, two old peasants (Ovid, Metam. 8:620). Hence the simple people of Lystra supposed, from the miracle on the cripple, that Paul and Barnabas were Mercurius and Jupiter once more visiting the earth "in the likeness of men." Mercurius being the god of eloquence, they called Paul Mercurius, the herald of the gods. Mercurius was usually figured a beardless youth, but there was an old Pelasgic figure of him bearded. Barnabas, the more stately and majestic in mien, they called Jupiter (2 Corinthians 10:10).

Bibliography Information
Fausset, Andrew R. Entry for 'Mercurius'. Fausset's Bible Dictionary. https://www.studylight.org/dictionaries/eng/fbd/m/mercurius.html. 1949.

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Mercurius