But in ancient times, Sunday – which was also known as the first day of the week, was also referred to as the eighth day by Christians.
This day was considered a holy day from the earliest of times by Christians (despite some weak arguments that Constantine, or the Pope, “changed the Sabbath” some 400 years later), and this was because it was the day on which Christ rose from the dead!
I will make a beginning of the eighth day, that is, a beginning of another world. For that reason, also, we keep the eighth day with joyfulness, the day on which Jesus rose again from the dead.
Barnabas, in his epistle, makes the first recorded mention of this day as specifically called the “eighth” which is as early as somewhere between 70 – 130 AD.
But the concept of an “eighth day” isn’t new and is found throughout the Scriptures in the Old Testament, specifically in the last of the great feasts: the feast of booths (Leviticus 23:33 onwards), and circumcision on the eighth day after birth. The priests and Nazirites also had seven days of cleansing before offering sacrifices specifically on the eighth day (Numbers 6, Leviticus 8:33ff).
The apostles pick up on these themes, like with the eight people, including Noah, who were “saved through water” (1 Peter 3:20) and how we now a spiritual circumcision of the heart instead of a physical proc… <a href="http://www.t
Source: That Ancient Faith