Two mitzvot constitute the basic elements of Shabbat: Zakhor (“commemorate”) and Shamor (“observe”). “Shamor” is a negative commandment to refrain from all labor. For six days, one must take care of his needs and productively engage the world, but on Shabbat we are enjoined to desist from all labor. By doing so, we clear space in our soul, which we are commanded to fill with the positive mitzva of Zakhor, whose content consists of commemorating the holiness of Shabbat and using it to connect with the fundamentals of faith.
These two mitzvot are so intimately linked that they are united at their root. They split into two complementary mitzvot only upon entering the human realm. This is the meaning of the Sages’ dictum: “Zakhor and Shamor were stated simultaneously, something that the human mouth cannot articulate and the human ear cannot hear” (Shev. 20b). We see this in the Torah itself: the Decalogue as reported in Shemot (20:8) introduces Shabbat with the word “zakhor,” whereas when the Ten Commandments are repeated in Devarim (5:12), it is replaced with “shamor.”
Zakhor is a positive commandment, rooted in love and the divine attribute of ĥesed (kindness). In contrast, Shamor is a negative commandment, rooted in the divine attribute of din (judgment), which sets boundaries so that man may turn away from wickedness. Positive mitzvot are at a higher level, as they enable people to come closer to God. However, the punishment for transgressing a negative mitzva is more severe, because it causes more serious damage, both to the sinner and to the world at large (Ramban, Shemot 20:7).
Zakhor is closely linked to the creation of the world and the first Shabbat, as the Torah states:
Commemorate (“zakhor”) the day of Shabbat to sanctify it…. For in six days the Lord made heaven and earth and sea, and all that is in them, and He rested on the seventh day. Therefore the Lord blessed Shabbat day and hallowed it. (Shemot 20:8-11)
The mitzva of Shamor is more closely linked to the Exodus from Egypt:
Observe (“shamor”) the day of Shabbat to sanctify it…for you were a slave in the land of Egypt, and the Lord your God freed you from there with a mighty hand and an outstretched arm; therefore the Lord your God has commanded you to keep the day of Shabbat.” (Devarim 5:12-15)
As a lofty spiritual principle, Shabbat was embedded in the world at its very creation. However, it was only after Israel survived the iron furnace of the Egyptian enslavement that they could understand how terrible it is to be subjugated to the material and how necessary it is to stop working in order to absorb the spiritual concept of Shabbat.
The two commandments – Zakhor and Shamor – are hinted at in the word “Shabbat.” Its simple meaning is related to the shevita, cessation of work, associated with Shamor. However, its deeper meaning is related to teshuva, “repentance” or “return,” for on Shabbat we return to the foundations of faith associated with Zakhor.