The mitzva to remember the lasting damage caused by Amalek, and our hope that what they did will one day be reversed, occurs in several places in our tefilla, but one might daven his whole life and not realize what he is saying.
The passuk says ויאמר כי יד על כס י-ה מלחמה לד' בעמלק מדר דר
Rashi:
כי יד על כס יה: ידו של הקב"ה הורמה לישבע בכסאו להיות לו מלחמה ואיבה בעמלק עולמית, ומהו כס, ולא נאמר כסא, ואף השם נחלק לחציו, נשבע הקב"ה שאין שמו שלם ואין כסאו שלם עד שימחה שמו של עמלק כולו, וכשימחה שמו יהיה השם שלם והכסא שלם, שנאמר (תהלים ט ז) האויב תמו חרבות לנצח, זהו עמלק שכתוב בו (עמוס א יא) ועברתו שמרה נצח, (תהלים שם) וערים נתשת אבד זכרם המה, מהו אומר אחריו (תהלים ט ח) וה' לעולם ישב, הרי השם שלם, (תהלים שם) כונן למשפט כסאו, הרי כסאו שלם:
For there is a hand on the throne of the Eternal: כִּי-יָד עַל כֵּס יָ-הּ. The hand of the Holy One, blessed be He, was raised to swear by His throne, to have a war and [bear] hatred against Amalek for eternity. Now what is the meaning of כֵּס [as opposed to כִּסֵא and also [why is] the Divine Name divided in half? [I.e., why is the Name יָ-הּ used instead of י-ה-ו-ה ?] [The answer is that] the Holy One, blessed be He, swore that His Name will not be complete and His throne will not be complete until the name of Amalek is completely obliterated. And when his name is obliterated, the Divine Name will be complete, and the throne will be complete....., as it is said: “The enemy has been destroyed; swords exist forever (לָנֶצַח)” (Ps. 9:7); this [who they are referring to] is Amalek, about whom it is written: “and kept their fury forever (נֶצַח)” (Amos 1:11). "And You have uprooted the cities-their remembrance is lost" (Ps. 9:7) [i.e., Amalek’s obliteration]. What does it say afterwards? “And the Lord (וַיהוה) shall sit forever” (Ps. 9:8); thus [after Amalek is obliterated] the Name is complete. "He has established His throne (כִּסְאוֹ) for judgment" (Ps. 9:8). Thus the throne is complete [i.e., thus the throne, here spelled with an “aleph,” is now complete]. — [from Midrash Tanchuma Ki Seitzei]
According to Rashi, the three letters which are lacking from Hashem’s Name and throne are א, ו, and ה, which can be rearranged to spell the word הוא. In other words, our verse teaches that Hashem has declared a war against Amalek in every generation. When this is finally won, the letters in the word הוא will be returned to their rightful places, at which time His Name and Throne will be restored to their complete glory and His kingship will be permanently established.
The sefer Avnei Shoham (and others) uses Rashi to reveal the meaning of words we say every day in davening. After Krias Shama, we say לדור ודור הוא קים ושמו קים וכסאו נכון ומלכותו ואמונתו לעד קימת. "For generation after generation (Le'dor va'dor), He (Hu) is established and His Name is established and His Throne (Kis'o) is firmly set and His kingdom and faithfulness is forever established. In light of our passuk and Rashi, we see that the words לדור ודור echo the words מדר דר– in our passuk, and that the words הוא קים mean that the letters in the word הוא, which have been diminished in our world, will be returned to their rightful places. After these letters are restored, we will see that שמו קים וכסאו נכון – Hashem’s name and throne are established and lasting, and מלכותו ואמונתו לעד קימת – His kingdom and faithfulness will be permanent and endure forever.
A reference in Kaddish:
From Sefer HaPardes/Rashi:
Tosfos Brachos 3a brings a corollary thought from the Machzor Vitri (written by Rav Simcha of Vitri, a pupil of Rashi) which explains that the congregational response to Yisgadal in kaddish, Yehei Shmei Rabba, is also a reference to this mitzva:
--A reference at the end of Davening: (guest emendation)
This is also reflected directly in the pasuk we say at the end of Aleinu- ביום ההוא יהיה ה' אחד ושמו אחד: i.e., on the day when the הוא is restored and the Name of Hashem is complete. On a deeper level, see the sugya Pesachim 50a on " אטו האידנא לאו אחד הוא ?" Note carefully the reference in that gemara to וזה זכרי לדר דר and the obvious connection to the parasha of Amalek --
A reference in Kaddish:
From Sefer HaPardes/Rashi:
בס׳ הפרדס לרש״י פי׳ קדיש. יתגדל ויתקדש כוי,והאיך יכול להתגדל שמו של הקב׳׳ה, שמא חס ושלום כביכול חסר הוא, אין וודאי חסר הוא, כדכתיב כי יד על כס יה,נשבע הקב׳׳ה שלא יהי׳ הכסא שלם עד שימחה זכר עמלק. וכן מצינו שמו ה׳, וכשהוא אומר כס יה אינו אלא חצי ה׳ באותיות, וכמו כן קורא לכסא כס, הרי שהן חסרין אותיות, לכך אגו מתפללים יתגדל ויתקדש, כלומר יהי רצון מלפני מי שאמר והיה העולם שיגאלנו מבין האומות וימחה את זכר עמלק ויתקדש שמו להיות שלם
In Kaddish, we say "May the infinite Name be made great and sanctified...." But is Hashem's name in need of being made great? Yes, it is, because after the attach of Amalek Hashem swore that His Name and His Throne are not entire until the effect of Amalek is erased. When it says Keis Kah, Kah is only half of the letters of Hashem's name, and Keis is half the letters of Kisei. We pray that they should be made entire, meaning, that He should redeem us from our exile and erase the name of Amalek and then His Name will be holy and entire.Tosfos Brachos 3a brings a corollary thought from the Machzor Vitri (written by Rav Simcha of Vitri, a pupil of Rashi) which explains that the congregational response to Yisgadal in kaddish, Yehei Shmei Rabba, is also a reference to this mitzva:
ועונין יהא שמיה הגדול מבורך, מכאן יש לפתור מה שפי׳ במחזור ויטרי יהא שמיה רבה, שזו תפלה שאנו מתפללין שימלא שמו, כדכחיב כי יד על כס יה, שלא יהא שמו שלם וכסאו שלם עד שימחה זרעו של עמלק, ופירושו כך: יהא שמי׳׳ה שם יה רבא, כלומר שאנו מתפללין שיהא שמו גדול ושלם, ומבורך לעולם הוי תפלה אחרת, כלומד ומבורך לעולם הבא. וזה לא נראה, מדקאמר הכא יהא שמיה הגדול מבורך משמע דתפלה אחת היא, ואינו רוצה לומר שיהא שמו גדול ושלם, אלא יהא שמו הגדול מבורך
Tosfos quotes the Machzor Vitri as saying that the response in Kaddish, Yehei Shmei Rabbah, is a prayer that Hashem's name be made whole, and the interpretation is as follows: The word Shmeih in Yehei Shmeih is a compound of Shem Yud Hei, which means the Name comprising the letters Yud and Hei; Rabba, may it be made whole again. The word Mevorach that follows begins another thought. Tosfos disagrees with this interpretation.--A reference at the end of Davening: (guest emendation)
This is also reflected directly in the pasuk we say at the end of Aleinu- ביום ההוא יהיה ה' אחד ושמו אחד: i.e., on the day when the הוא is restored and the Name of Hashem is complete. On a deeper level, see the sugya Pesachim 50a on " אטו האידנא לאו אחד הוא ?" Note carefully the reference in that gemara to וזה זכרי לדר דר and the obvious connection to the parasha of Amalek --