“Remember what Amalek did to you on your way out of Egypt. When they encountered you on the way, and you were tired and exhausted, they cut off those lagging to your rear, and they did not fear God. Therefore … you must obliterate the memory of Amalek from under the heavens.” (Deut. 25:17-8)
One of the 39 categories of melachah (work forbidden on the Sabbath) is to erase writing. There are, however, different forms of erasing. Erasing just to blot out what is written is a destructive act, and destructive acts are not forbidden on Shabbat by Torah law. Melachah is constructive activity, similar to God’s creative acts when creating the universe.
So what form of erasing is prohibited on the Sabbath? “Mocheik al m’nat lichtov” — erasing with the intention of writing again. One must intend to clean the writing surface in order to write over the original markings. This type of erasing is a positive, constructive activity, and therefore is incompatible with the special rest of the Sabbath day.
Restoring God’s Name and Throne
Rav Kook explained that this principle also applies to the mitzvah of ‘erasing’ Amalek. The mitzvah is not simply to obliterate Amalek in order that there will no longer be any more Amalekites in the world. That would be a purely destructive act.
What then is the mitzvah of destroying Amalek?
Amalek’s goal was to attack the nation who bears God’s Name in the world. Amalek could not tolerate the idea of a people with whom God made a special covenant, a people whose very existence implies ethical ideals and holy principles. The complete expression of the mitzvah to destroy Amalek is accomplished when we ‘erase in order to write.’ It is not enough to wage war against Amalek; the destruction of Amalek must have a productive goal. We must obliterate Amalek, and all that this evil nation represents, with the intention of “transforming the world into a kingdom of the Almighty.”
As the Midrash explains the verse in Exodus 17:16:
“God’s Hand is raised on His Throne: God shall be at war with Amalek for all generations.”
“Why is the word for ‘Throne’ shortened, and even God’s Name is abbreviated? God swore that His Name and His Throne are not complete until Amalek’s name will be totally obliterated.” (Tanchuma Ki Tetzei 11; Rashi on Ex. 17:16)
We must replace Amalek with the holy letters of God’s complete Name; and we must restore God’s complete Throne, through the special sanctity of the Jewish people.
(adapted from Mo’adei HaRe’iyah pp. 241-242)