"Remember the sabbath day, to keep it holy. Six days shalt thou labour, and do all thy work: But the seventh day is the sabbath of the LORD thy God: in it thou shalt not do any work, thou, nor thy son, nor thy daughter, thy manservant, nor thy maidservant, nor thy cattle, nor thy stranger that is within thy gates." (Exodus 20:8-10)
The Hebrew word for "remember" actually means to "mark" or "set aside." The Israelites didn't need to be told to "remember" the sabbath, because all nations had been keeping time in weeks ever since creation (Genesis 2:1-3). (Note the references to the sabbath in the sending of God's manna, prior to the giving of this commandment |Exodus 16:23-29|.) But they did need to be reminded to mark it as a holy or rest day, as God had done in that first week.
The Hebrew word for "sabbath" does not mean "Saturday" any more than it means "Sunday." It means, simply, "rest" or "intermission." The institution of the sabbath (that is, one day out of every seven days to be "set aside" as a day of rest, worship, and remembrance of the Creator) was "made for man" and his good (Mark 2:27). It was even of benefit to the animals used by man (note the mention of "cattle" in the commandment). It had been a pattern observed since the completion of God's six days of creation and making all things at the very beginning of world history (note Genesis 2:1-3; Exodus 20:11).
It is still appropriate today, as well. "There remaineth therefore a rest |that is, 'a sabbath-keeping'| to the people of God" (Hebrews 4:9). All men have a deep need to remember their Creator and His completed work of creation at least once each week, as well as His completed work of salvation—especially in these days when both of these finished works are so widely denied or ignored. HMM