ויהי חשך אפלה בכל ארץ מצרים שלשת ימים. לא ראו איש את אחיו ולא קמו איש מתחתיו שלשת ימים.
“And there was darkness over all of Egypt for three days. The people could not see each other; and no person could get up for three days.” (Shemos 10:22-23)
The plague of darkness lasted for six days. During the first three days, the people could not see each other, but during the next three days the plague intensified and actually paralyzed the people. The Egyptians were unable to move or even change positions, and they all remained frozen in place for three full days.
The Midrash tells us (Shemos Rabbah 9:12) that each plague lasted for seven days. The plague of darkness was an exception, as it only lasted for six days. On the seventh day, which was Shabbos, the darkness was lifted and light was restored to the Egyptians.
This shows us that in the midst of total darkness, when Shabbos arrives a new light comes forth and dispels the gloom. This is a tremendous source of chizuk to all of us. Every person goes through many difficulties in life. For example, a person may be struggling very hard to make ends meet. He toils endlessly and tries various jobs and ventures, but he repeatedly fails. When Shabbos comes, this holy day dispels the darkness of his unsuccessful week and infuses him with light.
This may well be the meaning of the words we sing in the Shabbos zemiros: “The laws of Shabbos that were given in [a place in the desert called] Marah were instructed with a warning.” The laws of Shabbos were given to the Jewish people in the desert before they received the Torah at Sinai. This shows us that while the world was still in darkness, before the light of the Torah illuminated the world, Hashem gave us Shabbos so that the Jewish people should have some light amidst the darkness.
The word Marah means “bitter.” That place in the desert was so named for the bitterness of the water that flowed there. The word azhara – warning, can also mean “light,” as we see in Daniel 12:3. We can now glean a new meaning from the above statement: “Shabbos was given in Marah, in bitterness, and instructed with light.” Even when a person experiences bitterness and darkness in his life, Shabbos has the power to illuminate his life and lift the darkness.