"Observe the Sabbath day by keeping it holy, as the LORD your God has commanded you. Six days you shall labor and do all your work, but the seventh day is a Sabbath to the LORD your God. On it you shall not do any work, neither you, nor your son or daughter, nor your manservant or maidservant, nor your ox, your donkey or any of your animals, nor the alien within your gates, so that your manservant and maidservant may rest, as you do. Remember that you were slaves in Egypt and that the LORD your God brought you out of there with a mighty hand and an outstretched arm. Therefore the LORD your God has commanded you to observe the Sabbath day."
The commandment to observe a day of rest was quite the revolutionary commandment for the Israelite people. There was no prior mandate in existence that commanded anyone to rest on any given day of the week. In essence, God was commanding the nation of Israel to cut their economic productivity by a full 1/7th when compared with the nations around them. Egypt, Babylon, Assyria - none of these nations had any limits on the number of days they could work in a week. Israel was forced to trust in God to provide where they had cut back in order to honor Him.
Perhaps just as revolutionary - ever notice how the verses go out of their way to repeat the fact that slaves should not work? No longer were the wealthy and powerful the only people in society that had the privilege of rest. The rest taken by the slaves would prove to be a regular reminder to the people that they were freed from slavery in a place where no rest was given. Here too the Israelite nation would have to trust in God to provide in those areas that they sought to honor Him by limiting their ability to produce.
We face the same dilemmas in today's day and age, they just have a different face. We have to learn not to work through the weekend because the client proposal is due first thing Monday morning. We need to be able to miss the 7:00pm meeting if it means not seeing our wife and kids in the evening. We must learn to say "no" to the opportunities to work hard enough to keep our performance level on pace with those who choose not to place limits on their work. And this means developing the deep faith and trust in God that he will provide in the areas that we limit our careers in order to properly honor Him.
Our lives are centered around our work - what we do for a living defines who we are. And so we are forced to ask ourselves the question: do we trust in ourselves and our own ability to work hard and long enough, or can we see our need for help, and rely fully on Him who is able to do "exceedingly more than we ask or imagine?"
7. As it is the law of nature, that, in general, a due proportion of time be set apart for the worship of God; so, in His Word, by a positive, moral, and perpetual commandment binding all men in all ages, He hath particularly appointed one day in seven, for a Sabbath, to be kept holy unto him: which, from the beginning of the world to the resurrection of Christ, was changed into the first day of the week, which in Scripture, is called the LordÂs Day, and is to be continued to the end of the world, as the Christian Sabbath.
8. This Sabbath is then kept holy unto the Lord, when men, after a due preparing of their hearts, and ordering of their common affairs before-hand, do not only observe an holy rest all the day from their own works, words, and thoughts about their worldly employments and recreations, but also are taken up, the whole time, in the public and private exercises of His worship, and in the duties of necessity and mercy. - from The Westminister Confession of Faith, chapter 21