The pasuk tells us to remember what Amalek did to us (Devarim 25:17). The Medrash Tanchuma (Ki Seitzei 69) states: “Yisroel said to Hashem: Master of the World, you want us to remember? You should remember! Forgetting is common for us but You never forget. Therefore, You should remember what Amalek did.”
The Bais Avrohom states that this is a great source of encouragement for us. He explains that a Yid often has thoughts to do teshuva but, since he is only flesh and blood, he soon forgets about it. This should not cause him to despair, as this is the will of Hashem.”
With this in mind, he explains two seemingly contradictory verses. One pasuk says to eradicate (timcheh) the memory of Amalek, which indicates that it is up to us to destroy this nation. Another pasuk, however, says that Amalek will be eradicated (macho emcheh), which indicates that Hashem will do it Himself.
He explains that we must start the process of eradicating Amalek. However, what we can do is limited as we are bound by human limitations, so Hashem, who never forgets and has no limitations, will then step in and do the rest.
