Two crucial mitzvot form the foundation of Shabbat: Zakhor (remember) and Shamor (preserve). These are addressed in the Ten Commandments: “Remember the Sabbath day and keep it holy” (Exodus 20:7) and “Observe the Sabbath day and keep it holy” (Deuteronomy 5:11). Shamor commands us to abstain from any creative labor. This generates a vacuum, which we are commanded to fill with content. Zakhor provides that content, because it involves remembering the foundations of faith, the sanctity of Shabbat, and Torah study.