"Timheh eth Zekher 'Amaleq Mittahath Hashamayim - Lo Tishkah" - You shall erase the remembrance of 'Amaleq from under Heaven. Do not forget.
The word Shamayim (Heaven) in Hebrew consists of the letters Sheen, Meem and Yod, (the additional Meem is just a repetition of the one before). The next letters that come after these in the Hebrew alphabet are Taw, Nun and Kaf, which form the acronym "Tanakh", which refers to the 24 books of the Torah. This comes to show us that for the merit of the Torah the name of 'Amaleq will be erased.
That is why it says, "Erase the remebrance of 'Amaleq fom under Heaven (Shamayim). Because under the letters of "Shamayim" are the letters "Tanakh", which is the written Law of the Torah, and for the merit of which, the name of 'Ameleq will be erased.
(See Addereth Eliyahu, Parashath Ki These)
