Remember the Sabbath Day, to Keep It Holy.

Exodus 20
7 Thou shalt not take the ^aname of the LORD thy God in ^bvain; for the LORD will not hold him ^cguiltless that ^dtaketh his name in vain.

8 Remember the ^asabbath day, to keep it ^bholy.

9 ^aSix days shalt thou ^blabour, and do all thy work:

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 ^astranger that is within thy gates:

11 For in ^asix days the LORD made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the LORD ^bblessed the sabbath day, and ^challowed it.

In Exodus 31:16 the Lord states that it is a "perpetual covenant". Dictionary.com define perpetual as "continuing or enduring forever; everlasting." Verse 17 reenforces this definition in this context: "It is a sign between me and the children of Israel for ever"

16 Wherefore the children of Israel shall keep the sabbath, to observe the sabbath throughout their generations, for a perpetual ^acovenant.

17 It is a sign between me and the children of Israel for ever: for in ^asix days the LORD ^bmade heaven and earth, and on the ^cseventh day he ^drested, and was ^erefreshed.

Verse 13 also states:

 13 Speak thou also unto the children of Israel, saying, Verily my ^asabbaths ye shall keep: for it is a sign between me and you throughout your generations; that yemay know that I am the Lord that doth sanctify you.

Elder Ezra Taft Benson quoted President George Albert Smith, "much of the sorrow and distress that is afflicting and will continue to afflict mankind is traceable to the fact that they have ignored his [God's] admonition to keep the Sabbath day holy" (Conference Report, Oct. 1935, p. 120; quoted in "Keeping the Sabbath Day Holy," Ensign, May 1971, 7).