The name Lord's Day
OriginsThe first appearance of the term kyriake hemera is in the New Testament, in the Book of Revelation, which was written in the latter decades of the first century.
In Rev. 1:10, the author writes, "I was in the Spirit on the Lord's Day." Most Christian commentators interpret Rev. 1:10 as a reference to Sunday, however this interpretation lacks contextual force since nothing in the passage implies he's talking about the first day of the week, Sunday. Also, the argument that the Lord's Day in Revelation 1:10 refers to the eschatological day of the Lord lacks contextual force as well since nothing in the adjacent passage implies the Second Coming or the Day of Judgment. Based on Jesus assertion that he was the "Lord of the Sabbath" (cf. Matt. 12:8), the "Lord's Day" of Revelation can only refer to the Jewish Sabbath, observed by Jesus and his Apostles.