Remember the Sabbath day, to keep it holy.

Exodus 20:8

Six days you shall do your work, but on the seventh day you shall rest; that your ox and your donkey may have rest, and the son of your servant woman, and the alien, may be refreshed.

Exodus 23:12

The Sabbath was to be a day free from all labor. It was a religious day. And it was a day of rest, not just for man, but even for the beasts of burden.

Does the New Testament shine any new light on the Sabbath? Yes, it does.

Formerly, when you did not know God, you were enslaved to those that by nature are not gods. But now that you have come to know God, or rather to be known by God, how can you turn back again to the weak and worthless elementary principles of the world, whose slaves you want to be once more? You observe days and months and seasons and years! I am afraid I may have labored over you in vain.

Galatians 4:8-11

Paul was never known for pulling punches. He warns the Galatians that they have turned to weak and worthless elementary principles of the world. (As a side note, notice "elementary principles." In Greek, this is stoicheion and shows up again in 2 Peter 3. It is these same elements that will be "burned up and dissolved." Not hydrogen, helium, lithium, etc.) They are weak - they cannot give life. They are also weak because Christ has now come and fulfilled them. They are worthless as they were only shadows of the grace and glory of Christ.

The Galatians, who were Gentiles, had begun observing the days, months, times, and years of the Jews. These ceremonies were absolutely unnecessary. A foolish bondage for the Gentiles. The Sabbath was a day of rest and now Christ, our Rest, our Sabbath has come. Because we are in Christ, we are always in our Sabbath. That shadow is no longer needed. So Sabbath observations, new moons, the Feasts of Tabernacles, Passover, and Pentecost, the seventh years and Jubilee - all disappeared in Christ - who is our Rest, our Sun of Righteousness, who became flesh and tabernacled with us, who is our Passover, who sent His Holy Spirit at Pentecost, our Jubilee, our Liberty.

Therefore let no one pass judgment on you in questions of food and drink, or with regard to a festival or a new moon or a Sabbath. These are a shadow of the things to come, but the substance belongs to Christ.

Colossians 2:16-17