The word that bothers me in that old hymn is “kings.” They most certainly were not kings. The Greek word for these men in Matthew 2:1-12 is “magi.” They were philosophers, astronomers, pagan astrologers, etc. One source I know calls them “walking universities.” They most likely came from what you and I would know in the modern world as Iran or Iraq. Rev. Dr. Paul L. Maier has a great chapter on the magi in his book, “In the Fullness of Time.” Thanks for your question!