From the book of Genesis:
2:1 Thus the heavens and the earth were finished, and all the host of
them.
2:2 And 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.
2:3 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.
From the book of Exodus:
20:8 Remember the sabbath day, to keep it holy.
20:9 Six days shalt thou labour, and do all thy work:
20:10 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:
20:11 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.
When you compare the two texts above you can see that the 4th Commandment was not first given to the Jews, but to Adam and Eve, the very first humans. It is also interesting to note that Jesus rose from the dead on the 1st day of the week, the day we all know was Sunday, but God has only blessed the 7th day of the week as is stated in both texts above.
(Note: Jesus said in Matthew 15:9 "in vain they do worship me...". Remember the story of Cain and Abel? Both Cain and Abel were attempting to worship God when they brought their offerings before Him, but only one gift was acceptable to God because it was what He had asked for. Cain, on the other hand, did things his own way and his worship was "in vain". This raises the question for us, "Is our worship "in vain" because we are doing things our own way, or are we worshiping God the way He wants?" There is one more verse that is important to keep in mind here. Acts 17:30 says, "And the times of this ignorance God winked at; but now commandeth all men every where to repent:")