After leaving Egypt and seeing the wonders of God’s greatness at the splitting of the Reed Sea, the Children of Israel prepared themselves for three days to receive the Torah at Mount Sinai. The Torah describes how God descended upon Mount Sinai in a fire, accompanied by thunder, lighting and shofar blasts (Exodus 19), and spoke to the Children of Israel. He taught them ten commandments before the people, feeling overwhelmed by the experience, requested that Moses speak to them instead of hearing directly from God (Exodus 20:16). The Ten Commandments have become the iconic encapsulation of God’s will.
The giving of the Ten Commandments appears twice in the Torah with subtle differences. In Exodus, the fourth commandment tells Israel to “remember” the Sabbath since God had made the world in six days and rested on the seventh:
Remember the Shabbat day and keep it holy. Six days you shall labor and do all your work, but the seventh day is a Shabbat of Hashem your God: you shall not do any work—you, your son or daughter, your male or female slave, or your cattle, or the stranger who is within your settlements. For in six days Hashem made heaven and earth and sea, and all that is in them, and He rested on the seventh day; therefore Hashem blessed the Shabbat day and hallowed it. Exodus 20:8-11
The connection between Shabbat and the creation is clear. Remembering the Sabbath pays tribute to the Creator and allows us to follow his example by resting on the seventh day.
But the reiteration of the Ten Commandments that appears in Deuteronomy has a different version of this commandment. The Israelites are told to “observe” the Sabbath because they were slaves in Egypt and redeemed by God with His mighty hand:
Observe the Shabbat day and keep it holy, as Hashem your God has commanded you. Six days you shall labor and do all your work, but the seventh day is a Shabbat of Hashem your God; you shall not do any work—you, your son or your daughter, your male or female slave, your ox or your ass, or any of your cattle, or the stranger in your settlements, so that your male and female slave may rest as you do. Remember that you were a slave in the land of Egypt and Hashem your God freed you from there with a mighty hand and an outstretched arm; therefore Hashem your God has commanded you to observe the Shabbat day. Deuteronomy 5:12-15
This iteration of the fourth commandment focuses on the observance of Shabbat as a commemoration of the Exodus of Egypt and God redeeming the Jews from slavery. The connection between Shabbat and the Exodus is more oblique. As slaves, the Jews were unable to observe Shabbat. The redemption from Egypt gave the Jews the freedom to serve their true master. But the precise day had been obscured under the harsh conditions in Egypt. The double portion of manna appearing on Friday reset the clock, reestablishing the Shabbat in its proper time.
The Midrash says that both versions of the Ten Commandments were spoken simultaneously as one utterance. The differences, spoken at the same time, reflect a duality of the nature of the Shabbat. This duality finds expression in many aspects of its observance, such as the two challot (loaves of bread) served at each meal and the lighting of two candles at the beginning of the sabbath. But these differences also have practical implications.
The version in Exodus commands Israel to “remember” the Shabbat, using the Hebrew word zachor (זכור), whereas the version in Deuteronomy uses the term shamor (שמור) to command the Jews to “observe” the Shabbat. In Torah law, these two terms have very specific implications.
Shamor (observe) refers to not transgressing the negative prohibitions of Shabbat. Torah law delineates 39 classifications of actions that are forbidden. The relevant laws are extremely complicated and have a marked effect on the nature of the day and how Jews act on Shabbat.
Zachor (remember) refers to the positive commandments used to sanctify the Shabbat. They are, in fact, relatively simple, consisting of kiddush (benediction recited over wine), Shabbat meals, lighting candles, and other actions focused on enjoying the day and making it special.