Establishing the Sabbath
The formal introduction of the Sabbath occurred at Mt. Sinai, when Moses received the Ten Commandments from Yahuah/God. The fourth commandment was an instruction to observe each seventh day as a Sabbath of the Lord.
"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 20:8-11).
God again stressed this particular commandment during Moses forty days and nights on Mt. Sinai, and added further detail:
" …Verily my Sabbaths ye shall keep; for it is a sign between me and you throughout your generations, so that ye may know that I am the Lord that doth sanctify you… whosoever doeth any work in the sabbath day, that soul shall be cut off. Wherefore 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 forever, for in six days the Lord made heaven and earth, and on the seventh day He rested and was refreshed." (Exodus 31:13-17).
God established the Sabbath as a perpetual (Hebrew: olam, an age, an indefinite time) covenant between Himself and the Children of Israel. Other nations and peoples were expected to observe these laws while they were within the gates of Israel, but the covenant was specifically with Israel.
Throughout the Sinai accounts of the Sabbath institution, Israel was reminded of the creative work of God, and of His resting on the seventh day. Israel, in their turn, were to rest as a reminder of their creating, sanctifying Lord. The theme of Sabbath is rest and remember!
Thus the institution of the Sabbath was established. From that time, and throughout the remainder of the Old Testament, the fact that the Sabbath was to be a day set apart was not questioned, although the actual observance of the Sabbath by the Children of Israel waxed and waned along with their spiritual prosperity.