במדבר טז,ג לַע וּלֲהָּק יַו-מֹשֶׁה וְעַל-אַהֲרֹן, וַיֹאמְרוּ אֲלֵהֶׁם רַב-לָּכֶׁם--כִּי כָּל-הָּעֵדָּה כֻּלָּם קְדֹשִּים
“Because all the congregation in its entirety is holy.” Why did the verse say “all” twice?
I.
The words of the Ta"z in hilchos Rosh Hashanah (O.C. 582, note 3) are well known.
כולו בכבודך מלוך על כל העולם אלוקינו ואלוקי אבותינו
He posits that we say "M'loch al KOL ho'olom KULO," (in the Amidah) and there is no redundancy. Had we only said this phrase without the added KULO we might understand that we pray that Hashem reign upon the majority of the world, as KOL literally meaning ALL can be used for the majority only as well, by virtue of the dictum "rubo ch'kulo," - a majority is like all. By adding the word KULO it is undisputedly literally ALL.
II.
Perhaps here too, קְדֹשִּים הָעֵדָה כֻּלָם-כָלכִּי had Korach only said "ki kol ho'eidoh k'doshim," and left out the word KULO, then we might understand this to mean the MAJORITY. Adding KULO teaches us that he meant absolutely everyone is holy.
III. Tanya first perek
תהי צדיק ואל תהי רשע, ואפילו כל העולם כולו אומרים לך צדיק אתה היה בעיניך כרשע
“Be righteous and be not wicked; and even if the whole world judging you by your actions tells you that you are righteous, regard yourself as wicked.”
Here too the emphasis is that not just the majority but even if everyone tells you that you are righteous, nevertheless you must regard yourself as if you are wicked.
Commentators:
Shem Shmuel states that when all the Jews crown HaShem as the King through the various methods on Rosh HaShana, then the Jews can be victorious in the Judgement.
The Ariz”l states that if all year the Jews should say prior to prayer “I now accept upon myself the positive commandment of ‘Love your fellow Jew like yourself’” (as mentioned by the Magen Avrohom, the Shulchan Aruch ha Rav, Rabbi Shlomo Zalman Auerbach and others) then for sure it is proper to include all Jews within your prayers to make one group with the beginning of the New Year.
Eitz Yosef adds that we not only include all Jews, we also include the entire world and all its inhabitants. We are crowning HaShem as master of “all” without exception.
Chizkuni seems to be offering a different interpretation. He says that Korach only referred to the firstborn. The reason he said that they were holy is that the Torah itself says that the firstborn are holy, "Ka'desh li kol b'chor" (Shmos 13:2). Possibly this is in consonance with the above. Although limited to the firstborn only, but he meant absolutely EVERY firstborn.
Medrash haNifla that indicates that when Dovid haMelech saw this verse in Parshas Korach, he took his harp and uttered what became the 30th chapter of Tehillim:
“A psalm; a song of dedication of the House, of David. I will exalt You, O Lord, for You have raised me up, and You have not allowed my enemies to rejoice over me.”
Dovid’s intention was that he recognized that all the Jews were holy and would follow the decrees of Chaza”l. He had feared that only most would follow the decree to give their wives a Get prior to going out to war, but not all. Perhaps Uri had been in a minority that did not give a Get and Dovid had committed a sin with Batsheva. However, now he understood that all were holy that went out to war and all following the decree to give a Get and Dovid had not committed such a large sin.
