Korach תרל”ו 3-4

ואהרן מה היא כו’
(Bamidbar 16:11) “And what is Aharon that you complain about him”
פי’ שזה הי’ בחי’ אהרן הכהן איש חסד פי’ שיכול לקבל החסד כראוי.
The explanation is that the concept of Aharon, is that he is called ‘the man of kindness’. This means that he is able to receive kindness properly.
וז”ש עבודת מתנה אתן את כהונתכם והזר הקרב יומת.
This is the idea of “I give them a service that is a gift, and the foreigner who shall come close will die”
פי’ כיון שבחי’ אהרן רק במתנת עליון לכן א”י לשלוט בו שום פני’ והזר הקרב יומת
This means that the idea of Aharon is completely a gift from HaShem, and therefore any foreigner – (meaning any selfish motivations), cannot be withstood. As it states “and the foreigner…shall die”.
אבל מי שבא לזכות עפ”י דין צריך לשמור עצמו מאוד ולצרף לזה בקשת רחמים רבים מהשי”ת:
However if someone comes and demands greatness (not as a gift, but) as a right, he needs to be extremely cautious (that it is not motivated by selfish reasons) and to combine it with plentiful supplications of mercy from HaShem.

מה שביקש מרע”ה דוקא לענשם בענין זה שאמר אם לאו יברא עתה וכי לא הי’ יכול לעונשם בעונשין שנבראו כבר במעשה בראשית.
(The reason) why Moshe Rabeinu requested that (Korach and his crew) will be punished by a new creation (that the earth should swallow them up, needs explanation). Could they not have been punished with punishments that had already been in existence the creation of Heaven and Earth?
וי”ל עפ”י מ”ש חז”ל וקרח שפקח הי’ ראה שלשלת גדולה יוצאה כו’. וקשה הלא גם הוא ידע שיכולין בניו לשוב בתשובה.
However we can explain this based on the words of our sages (Bamidbar Rabbah 18:8) Why did Korach, who was very clever, fall into this foolishness of challenging Moshe and Aharon? It was because he saw through prophecy a great lineage in his children, and thought that if his children are great it must mean that he too is destined for greatness.
Now this in itself is difficult, Korach was also aware that it could be that his descendants would repent (How does their greatness reflect on his decisions)?
אכן יראה ודאי הבין קרח כי לפי גדולתן של בני קרח אח”כ אם הי’ נשאר להם החטא מאביהם שנטה מדרך האמת לא היו יכולין להיות במדריגה זו העליונה. כי מכל חטא האדם נשאר לדורות מעט כמאמר פוקד עון אבות כו’. ובני קרח הי’ מעלתם גדולה מאוד.
However, it would seem that clearly Korach understood that since his children were destined to be so great, if their father had indeed strayed so far from the correct path, they would not attain such a high level of greatness. This is because such a severe sin would have left a stain on them, and prevent them from attaining such greatness.
For every sin leaves a mark for generations to come, as it states (Shemos 34:7) “He visits the iniquity of the parents on their children”. Yet Korach’s children attained an extremely high level.
ולכן הי’ מוכרח להיות יורד חיים שאולה ואז לא ירשו בניו מחטא שלו כלום ונשתנה עליו סדרי בראשית.
It was for this reason that (a new creation had to be created and destroy Korach. That he must) fall to destruction while still alive and his children will not inherit any of his sin. This is why the entire creation had to be changed (to punish Korach).
ולכן נכשל קרח שלא עלה על דעתו להיות שינוי סדר העולם בעבורו. לכן סבר שהאמת אתו.
It was because Korach did not consider such a possibilty, that the entire creation would chagne just for him, that he thought (the only possible way for his children to attian such greatness must be) that he was correct (in his argument against Moshe).
[Possibly a false sense of humility] ויש רמז לזה במסורה שהביא בעל הטורים ופקודת כל האדם יפקד כו’ שלא ישאר העונש לבניו כמ”ש פוקד עון אבות כו’ ע”ש.
This too is hinted to in the words of the Ba’al Haturim. On the pasuk (Bamidbar 16:29) “If these people death ופקודת is that of all humankind”. The Ba’al Haturim explains that this means that the punishment will not be passed on to their children (as it usually is), as it states: (Shemos 34:7) “He visits פוקד the iniquity of the parents on their children”
ויובנו הדברים יותר עפ”י דברינו.
In light of what we have explained this is better understood.
לכן נאמר ויאבדו מתוך הקהל.
It is for this reason why the Torah specifies (Bamidbar 16:33) “And they were lost from the nation”.
פי’ שכל מי שמסתלק מעוה”ז במיתה יורשין בניו מקומו ונשאר כחו בכלל הקהל. אבל הם שירדו חיים נאבדו הם ומעשיהם מכלל הקהל כנ”ל:
This means that usually someone who leaves this world by death, their children inherit their place, and their energy remain among the nation. However, since they fell to gehinnom while still alive, their entire actions were removed from the nation, as explained above.