Deuteronomy 5:15

And remember that thou wast a servant in the land of Egypt, and that the Lord, thy God, brought thee out thence through a mighty hand and by a stretched-out arm, an expression denoting the exercise of God's almighty power; therefore the Lord, thy God, commanded thee to keep the Sabbath-day. The fact that Israel was the redeemed people of God and thus distinguished by Him above all nations was to be brought out in their Sabbath observance. The Sabbath-day, as a day of rest by God's command, has been abrogated in the New Testament, and we Christians do not transfer to any other day the special ceremonial prohibitions which attached to the Sabbath of old. Cf Matthew 12:8; Mark 2:28; Galatians 4:9; Colossians 2:16. But the principle of the commandment is in force today as it ever was. It has been most succinctly and successfully stated by Luther: "We should fear and love God that we may not despise preaching and His Word, but hold it sacred, and gladly hear and learn it. "