The two times the 10 commandments are given, in Exodus 20 (the first time) and in Deuteronomy 5 (re-stated) contain some differences. One is the evident different reason given for the Sabbath command. Read for yourself:
Exodus 20:8-11 ESV – 8 “Remember the Sabbath day, to keep it holy. 9 Six days you shall labor, and do all your work, 10but theseventh day is a Sabbath to the LORD your God. On it you shall not do any work, you, or your son, or your daughter, your male servant, or your female servant, or your livestock, or the sojourner who is within your gates. 11For in six days the LORD made heaven and earth, the sea, and all that is in them, and rested on the seventh day. Therefore the LORD blessed the Sabbath day and made it holy.
Deuteronomy 5:12-5 – 12“‘Observe the Sabbath day, to keep it holy, as the LORD your God commanded you. 13Six days you shall labor and do all your work, 14but the seventh day is a Sabbath to the LORD your God. On it you shall not do any work, you or your son or your daughter or your male servant or your female servant, or your ox or your donkey or any of your livestock, or the sojourner who is within your gates, that your male servant and your female servant may rest as well as you. 15 You shall remember that you were a slave in the land of Egypt, and the LORD your God brought you out from there with a mighty hand and an outstretched arm. Therefore the LORD your God commanded you to keep the Sabbath day.
Genesis gives a Creation-related explanation and Deuteronomy gives one related to the Exodus. In the first case, we rest because God “rested” from his work of creation. In the second case, we rest because God’s salvation liberated them from the bondage of oppressive work under the hand of slave-drivers.
Since God’s rest is not caused by the Almighty growing tired, we look for a reason. John Walton suggests that when a god rested, in ancient near east religions, it meant that he took his place in a temple. Genesis then is saying that the Lord on the 7th day was done with the initial creative act, and that he fully inhabited his universe as the One who is in charge. We Rest then not in imitation (bc our “rest” is different that God’s “rest”), but in trust.
The oppression of work was the life of the Slaves in Egypt – the very concept of slavery is that a person is only meaningful so far as his or her work provided value. Now Israel has a newer Master, it is no longer the Pharoah. This new Master gives them one day in 7 without work. This is a reminder that life is more than work and the things that work produces. Note that servants and aliens in Israel were also to keep the Sabbath rest.
We should observe the Sabbath, because it goes back to the beginning, beyond the covenant law of Israel. Since we know the Lord is Lord, we can rest. We should observe it also because life is more than work, food, clothing and money.