The sons of Korach did not die.
Be’er Yosef: While the pasuk leaves us hanging, Rashi fills in the missing details. Korach’s sons had been full participants in the rebellion. They later felt remorseful. Therefore, while all the others perished when the earth swallowed them up, a place was set up for Korach’s sons on an elevated place in Gehinom, and they took up residence there.
They didn’t disappear from history. Rashi omits one point that the gemara from which he took his commentary. The gemara relates what Korach’s sons do on their Gehinom-balcony: they sing shirah. We don’t have to look far to find their trademark song. “For the conductor, on the shoshanim…by the sons of Korach…: My heart stirs with a good thing. I say, ‘My works are for the king.’”
A startling observation emerges from this fuller picture of the episode. The song that they composed amounts to an exact-fit teshuvah exercise for Korach’s sons. The central premise of their rebellion – the idea they marketed and sold to the public – was the purported abuse of power of Moshe and Aharon. The Korach rebellion sought to re-image them as tyrants, who even used the laws they promoted as tools through which to oppress the people. One midrash, for example, has Korach and his henchmen speaking to the people about a poor widow neighbor of theirs whose meager holdings were reduced to nothing by a succession of demands by Moshe for the gifts to kohanim and leviim.
The antidote to this poisonous image is the chapter in Tehillim that Korach’s sons authored, because it speaks lovingly of Torah scholars. It is a perfect foil to the hateful negativity towards them that was promoted by the rebellion. Thus, the reference to shoshanim, which may refer to a musical instrument, but alludes to roses, which in turn are likened to talmidei chachamim. Torah scholars are soft and supple – the opposite, really, of the harsh tyrants that their father had depicted Moshe and Aharon. In truth, the two brothers were the most humble of people – as soft as can be.
Some will object that by the gemara’s own instruction, talmidei chachamim are supposed to be anything but soft and supple. “Any talmid chacham who is not hard as iron is not a true talmid chacham.” The objection cannot be sustained. It is true that some talmidei chachamim are required to be strong and unyielding – but only some. Those in positions of authority – whether political or legal – need to show strength so that their decisions will be obeyed, and therefore effective. Talmidei chachamim, however, who devote themselves to Torah study and are not appointed to positions of leadership – they must exhibit the softness and pleasantness (a characteristic of Torah itself) of roses.
There is further nuance to this distinction between ordinary Torah scholars and those in positions of authority. While the latter must often wield power, they too must at their core be soft like roses. They must deal with strength from time to time, but they should remain soft and pleasant at all other times. This is borne out by the accolades bestowed upon R Yochanan ben Zakai by his students: “Light of Israel! Right-most pillar! Strong Hammer!” As the nasi, R Yochanan ben Zakai was forced to act like a strong hammer at times. Yet, he remained the right-most pillar, a reference to the characteristic of chesed that is associated with the right. While at times hard as iron, at his essence he was soft and pleasant.
We should also take note of the opening of the shirah sung by Korach’s sons: “My heart stirs with a good thing.” These sons had been part of an open rebellion against the most faithful of Hashem’s servants – a rebellion that threatened the transmission of Torah for all generations, by questioning the reliability of Moshe’s instructions. They took part in all of their father’s cynical mockery of some of Moshe’s teaching, in effect mocking the Torah itself. They did not have a change of heart until they felt the rumblings of the earth beneath them. They were so quickly swallowed up, that they had no opportunity to voice or even think of full remorse. There was only time for a vague stirring of the heart, the beginnings of what ordinarily be a long process of teshuvah.
Yet, HKBH treated those stirrings lovingly, accepting them as if they were linked to fuller teshuvah. This proto-repentance was so effective that it not only saved them from descent to the depths of Gehinom, but it elevated them to the point that they experienced ruach ha-kodesh. Through that spirit from on high, they were able to sing shirah about the future.
 Based on Be’er Yosef, Bamidbar 26:11
 Sanhedrin 110A
 Tehillim 45:1-2
 Taanis 4A
 Berachos 28B
 In contradistinction to judgment/ din, which is associated with the left