Ask any schoolchild “When is Shabbat?” and she will tell you what we all know: Shabbat is the seventh day. But this is not always the case, as Parashat Emor teaches us.
The two verses quoted above each use the word Shabbat, but the word refers not to the seventh day of the week, but to the seventh month of the year. In the first example, the words Shabbat refers to the holiday of Pesach (which is the seventh month if you count from Tishre); in the second example, Shabbat Shabbaton means Yom Kippur (which is the seventh month if you count from Nisan).
But why does the Torah use the word Shabbat to mean both the seventh day and the seventh month? My teacher, Rabbi Saul Berman, answered this by teaching that the fundamental purpose of Shabbat is to allow us to withdraw from vital activities in order to reflect and evaluate the role they play in our lives. On the seventh day, we withdraw from production (melachah) in order to evaluate our relationship to it, thereby ensuring that we don’t define ourselves or our relationships solely by what we produce.
Yom Kippur and Pesach take this same concept one step further, restricting not only what we produce but also what we consume, in order to reflect on our attitudes towards consumption. While the Shabbat of days helps us not to define ourselves (or others) by “what we do”, the Shabbat of months (Pesach and Yom Kippur) keep us from defining ourselves by “what we have”. When we observe these holidays well, we enter into the true meaning of Shabbat, being reminded of the One who is the true Source of everything we have and everything we do.