Epiousios

The unique word epiousios—a quote of Jesus Christ, and contained only in the Lord's Prayer (Matthew 6:11 and Luke 11:3)—is not found anywhere else in the original scriptures of the Bible, nor anywhere else in all of ancient Greek literature, and so its meaning relies upon linguistic parsing. It is used solely as an adjective (Koine Greek: επιούσιον) that qualifies the accompanying word "bread."

By tradition, the most common English language translation is daily, though most scholars today reject this. While epiousios is often substituted by the word "daily," all of the other New Testament translations from the original Greek phrases into "daily" otherwise reference hemeran (ἡμέραν, "the day"), which does not appear in this usage.

The challenge in translating epiousios goes at least as far back as 382 AD, well over 1,000 years prior to the creation of the world's first printing press and the Gutenberg Bible in the 1450s. In that era, St. Jerome was commissioned by Pope Damasus I to renew and consolidate the various collection of biblical texts in the Vetus Latina ("Old Latin") then in use by the Church. Jerome accomplished this by way of going back to the original Greek of the New Testament and translating it into Latin, and over hundreds of years later his research and translation became known as the Vulgate. In the identical context—that is, appearing in the Lord's Prayer—Jerome translated epiousios in two completely different ways: via linguistic parsing as supersubstantial in Matthew, while retaining the traditional but linguistically controversial daily interpretation in Luke.

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