The next purpose was to set a seal of sanctity upon the Sabbath. In the second chapter of Genesis we read—
"On the seventh day God ended His work which He had made; and He rested on the seventh day from all His work which He had made. And God blessed the seventh day, and sanctified it: because that in it He had rested from all His work which God created and made."
In this we get the institution of the week, the first ordinance imposed by God upon man. For in the fourth of the ten commandments which God gave through Moses, it is said—
"The seventh day is the sabbath of the Lord thy God: in it thou shalt not do any work. . . . For in six days the Lord made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the Lord blessed the sabbath day, and hallowed it."
And again, when the tabernacle was being builded, it was commanded—
"The children of Israel shall keep the sabbath, to observe the sabbath throughout their generations, for a perpetual covenant. It is a sign between Me and the children of Israel for ever: for in six days the Lord made heaven and earth, and on the seventh day He rested, and was refreshed."
God made the sun, moon, and stars, and appointed them "for signs, and for seasons, and for days, and years." The sun marks out the days; the moon by her changes makes the months; the sun and the stars mark out the seasons and the years. These were divisions of time which man would naturally adopt. But there is not an exact number of days in the month, nor an exact number of days or months in the year. Still less does the period of seven days fit precisely into month or season or year; the week is marked out by no phase of the moon, by no fixed relation between the sun, the moon, or the stars. It is not a division of time that man would naturally adopt for himself; it runs across all the natural divisions of time.
What are the six days of creative work, and the seventh day—the Sabbath—of creative rest? They are not days of man, they are days of God; and our days of work and rest, our week with its Sabbath, can only be the figure and shadow of that week of God; something by which we may gain some faint apprehension of its realities, not that by which we can comprehend and measure it.
Our week, therefore, is God's own direct appointment to us; and His revelation that He fulfilled the work of creation in six acts or stages, dignifies and exalts the toil of the labouring man, with his six days of effort and one of rest, into an emblem of the creative work of God.