This week is Parshas Zachor, and the Haftorah is Shmuel I:15, which begins like this:
ויאמר שמואל אל שאול אתי שלח ה' למשחך למלך על עמו על ישראל ועתה שמע לקול דברי ה'צבאות פקדתי את אשר עשה עמלק לישראל אשר שם לו בדרך בעלתו ממצריםעתה לך והכיתה את עמלק והחרמתם את כל אשר לו
Some people begin reading from the first passuk, and others begin from the second passuk, like so:
According to the Oneg Yomtov, the Rambam holds that the Mitzva of Mechiyas Amalek only pertains to the Melech. The Mitzva only begins when there is a king, and as soon as there is no king, the mitzva of Mechiyas Amaleik immediately ends. Here is the Oneg Yomtov (in letter Vov):
The Ramban on Shemos 17:16 says pretty much the same thing:
The Chinuch, on the other hand, holds that although the Gemara in Sanhedrin requires that we anoint a king before we attack Amalek, the mitzva is triggered as soon as a king has been appointed, and the mitzva remains in effect forever, with or without a king, and is incumbent upon every individual in Klal Yisrael. Or you could read it to mean that there is an ikkar mitzva and a non-ikkar mitzva, but even the non-ikkar mitzva is a mitzva, like Bilah by a Korban Mincha. The Chinuch is in Mitzva 604 (some older editions don't have all the words of the Chinuch):
So if you hold like the Rambam, you have to begin the Haftorah with the first passuk that says that Shaul was anointed king, because without a king, there is no mitzva. In fact, the Rambam in 1 Melachim 2 brings this passuk to prove that appointing a king precedes mechiyas Amalek- מינוי מלך קודם למלחמת עמלק. שנאמר אותי שלח ה' למשחך למלך עתה לך והכיתה את עמלק. But according to the Chinuch, having a king no longer matters, and the mitzva pertains with or without a king. Therefore the haftorah should begin with the second passuk, which directly addresses the Inyana de'Yoma.
I am aware of the Rambam that also says that every individual is over a lav if he refrains (5 Melachim 4,5- מצות עשה להחרים שבעה עממין שנאמר החרם תחרימם. וכל שבא לידו אחד מהן ולא הרגו עובר בלא תעשה שנאמר לא תחיה כל נשמה. וכבר אבד זכרם: וכן מצות עשה לאבד זכר עמלק. שנאמר תמחה את זכר עמלק,) and I agree that it is very possible that all the Rishonim basically agree that the Mitzva is on the Tzibur and it devolves from the Tzibur to its component yechidim. But I am working with the Oneg Yomtov, and according to the Oneg Yomtov there is a very big difference between the Rambam and the Chinuch. Also, the Rambam in Sefer Hamitzvos after Asei 248 says
The Magen Avraham in OC 60 SK 2 brings from the אר״י ז״ל in the Kavanos that there are Zechiros, things that we should remember, and that they are listed in the Bracha before Krias Shma, in Ahava Rabba. You might know it as Ahavas Olam. In any case, many of us are not aware of this subtext, so here's the Magen Avraham.
- כשיאמר ובנו בחרת יזכור מ"ת,
- וקרבתנו מעמד הר סיני,
- לשמך הגדול מעשה עמלק שאין השם שלם,
- להודות לך הפה לא נברא רק להודות ולא לדבר לשון הרע וזהו זכירת מעשה מרים,
- וזכרתם את כל מצות ה' זהו שבת ששקולה כנגד כל המצות
And here is what the Aruch Hashulchan says about this, so you shouldn't feel bad if you never did what the Magen Avraham recommended:
UPDATE: Thank you to the Anonymous commenter who explained that the Aruch Hashulchan is talking about the minhag to drop the tzitzis after saying "מארבע כנפות הארץ", and it has nothing to do with the Zechiros.
There are many opinions about what the chiyuv of zechira from a sefer entails. In the Maaseh Rav, the Gaon is said to have layned himself, and most people understand this to be because Miztva bo yoser mibishlucho. In the Sefer Yeshodei Yeshurun, by Rabbi Felder, who can be trusted, he says that Reb Moshe's shitta was that you are yotzei by hearing it being read, and not because of shlichus or shomei'a k'oneh, but simply because the whole chiyuv is to hear it. This is diametrically opposed to the Taz that holds that being yotzei the Bracha of Krias Hatorah is essential to being yotzei the mitzva of Zechiras Mechiyas Amalek.
We are all familiar with the Brisker chiddush that the definition of Amalek regarding the Mitzva of Mechiyah is not specific to the ethnic group that descended from Eliphaz, but includes every person that wants to destroy Klal Yisrael. In the US, people say it from the Rav in the name of his father, but Rav Shternbuch in Teshuvos V'Hanhagos says it in the name of Reb Chaim. What I found more interesting is the appellation Amalek for divisive Jews in the Even Shleimah from the Gaon, here: