Eighth day has a special relevance in the Bible. The Genesis frames the creation narrative within a week, including the Sabbath day. Since the eighth day is a new week’s beginning, the Bible considers it as a day of fresh start.
The covenant with Abraham through circumcision was a new beginning of salvation. “Circumcise the flesh of your foreskin. That will be the sign of the covenant between me and you” (Lev 17:11). God selected the eighth day for circumcision, regardless of Sabbath observance. The Israelites considered seven days as days of purification and the next day the day of sanctification. A male child, along with his mother, was unclean for seven days. Then they circumcised him on the eighth day (Lev 12:2-3).
During the deluge, God saved only Noah’s family of eight to renew the world.
In the New Testament, “eighth” day and “first day of the week” are the same. Jesus rose from the dead on the “first day of the week” (Mt 28:1). Jesus appeared to his disciples several times “on the first day of the week” in between his resurrection and ascension. Pentecost was also on the first day of the week. The early Christians kept the first day as holy day and called it the Lord’s Day (Rev 1:10) replacing the Jewish Sabbath (Acts 20:7; 1 Cor 16:2).
Animals were unacceptable for sacrifices until the eighth day of their birth. “The Lord said to Moses: When an ox or a lamb or a goat is born, it shall remain with its mother for seven days; only from the eighth day onward will it be acceptable, to be offered as an oblation to the Lord” (Lev 22:26-27). The reason for uncleanness of animals was not because they were born in sin like descendants of Adam and Eve, but because they were offered in the Temple in the place of the first-born children.
People who were unclean through leprosy or any defilement had to observe seven days of purification. On the eighth day, they were accepted as clean (Lev 14:8-10; 15:13-14; Num 6:9-10).
The purification of the altar, vessels used in the holy place, and the priests, took seven days. Their purity was established only on the eighth day (Ezek 43:26-27). Thus, seven days were days of purification and the eighth day was for sanctification.
Every Sunday is the eighth day and a day of our spiritual renewal. Instead of the Sabbath, we observe that day holy by partaking in the Holy Sacrifice of Jesus in the church. That also should be a day strengthening of our family bond, building relations with fellow Christians, service to the church, and charitable service.