Deuteronomy 25:17

Keep in mind what the house of Amalek did unto you in the way, on your coming up out of Mizraim;

REMEMBER WHAT AMALEK DID UNTO THEE. I have already mentioned the Midrash which the Rabbis interpreted in the Sifra:. “I might think that it means, ‘in your heart.’ But when Scripture states, thou shalt not forget, 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, 296. “Remember what Amalek did unto thee means verbal [remembrance]. Thou shalt not forget 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! 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]! 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 commanded 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, yet Scripture commanded that it be made known and revealed so that the admonition against slander be put in their mouths 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: “All people are [suspect] of a shade of slander.”
Ki Thavo