Commentaire sur Le Deutéronome 25:17

זכור את אשר עשה לך REMEMBER WHAT [AMALEK] DID UNTO THEE — If you use false weights and measures then you must apprehend the provocation of the enemy, as it states (Proverbs 11:1): “A false balance is an abomination to the Lord, etc.”, and there is written immediately after this (v. 2): “If intentional sin comes, shame comes”(Midrash Tanchuma, Ki Teitzei 8).

REMEMBER WHAT AMALEK DID UNTO THEE. I have already mentioned the Midrash which the Rabbis interpreted in the Sifra:³⁸⁰Above, 24:9. The Sifra quoted is at the beginning of Seder Bechukothai. “I might think that it means, ‘in your heart.’ But when Scripture states, thou shalt not forget,³⁵³Further, 25:19. forgetfulness of heart is already stated. How then can I fulfill the injunction Remember? It must mean ‘by verbal utterance.’” It is also stated in the Sifre,³⁸¹Sifre, Ki Theitzei 296. “Remember what Amalek did unto thee means verbal [remembrance]. Thou shalt not forget³⁵³Further, 25:19. means [remembrance] in the heart.”
But I know not what is this remembrance through the spoken word. If it is to say that we are to read the section of Amalek in public, then we might deduce therefrom that the duty of reading on the second [Sabbath in the month of Adar the section] Remember what Amalek did unto thee is by law of the Torah!³⁸²Megillah 29b. On each of four Sabbaths preceding the month of Nisan there is a special Scriptural section read during the Synagogue service. On the Sabbath immediately preceding Adar we read the section of the shekels; on the Sabbath before Purim we read the section before us on Amalek because Haman was a descendant of Agag, king of the Amalekites — Now it is known that the reading of the Torah in public was ordained by Moses and the prophets (Baba Kamma 82a). But, concludes Ramban, according to the above interpretation we may thus say that the reading of the section on Amalek in public is ordained by the Torah! See Shulchan Aruch, Orach Chayim 685:7, where this opinion is mentioned. So also we shall have in that case a Scriptural support for the reading of the Scroll [of Esther on Purim]!³⁸³See Ramban above, 4:2, as to how the Sages had difficulty in establishing this duty. But, concludes Ramban, in the text before us we have Scriptural support for the reading of the Scroll of Esther, since this is a form of “verbal remembrance.” However, since the Rabbis made no reference to it we must say that the correct interpretation of the text is as follows. The correct interpretation appears to me that the verse states that you are not to forget what Amalek did to us until we blot out his remembrance from under the heavens, and that we are to relate it to our children and to our generations, saying to them, “Thus did the wicked one do to us and therefore we have been commanded to blot out his name.” Similarly, in the affair of Miriam, we were commanded³⁸⁴Above, 24:9. to make it known to our children and relate it to the generations. And although it would have been appropriate to conceal it in order not to speak of the shortcomings of the righteous,³⁸⁵Sanhedrin 93b: “And does Scripture speak of the shortcomings of the righteous?!” yet Scripture commanded that it be made known and revealed so that the admonition against slander be put in their mouths³⁸⁶Further, 31:19. because it is a great sin and causes many evils, and people are in the habit of stumbling therein, just as the Rabbis have said:³⁸⁷Baba Bathra 165a. “All people are [suspect] of a shade of slander.”
Ki Thavo

זכור את אשר עשה לך עמלק, "Remember what Amalek did to you, etc." The reason the Torah singles out Amalek is because this nation was unique, attacking the Israelites by seeking them out, not even knowing where they were to be found. Just as an eagle flies far and wide to search for prey, so the Amalekites marched through hundreds of miles of desert in order to locate the Israelites.