The Torah tells us that Korach and his fellow rebels were swallowed alive by the earth. However, we are also told (in Parashat Pinchas) that the sons of Korach did not die. The commentators differ in their understanding of this situation. Some commentators imply that Bnei Korach sank into the ground but remained “alive,” perhaps to this day. Perhaps they are still singing; Sefer Tehillim has a few chapters attributed to Bnei Korach in which they prophesied. Others commentators, such as Ramban, explain that since Shemuel HaNavi descended from Korach (as stated explicitly in Sefer Divrei HaYamim), Bnei Korach must have been spared completely. Additionally, the Torah still refers to the family of Korach after this episode, implying that some part of it survived.
Korach also had 250 people with him in his rebellion. The commentators explain that these included Korach’s servants, other parts of his family and perhaps other, unrelated members of Bnei Yisrael (see Rashi to BeMidbar 16:1 s.v. VeDatan).
Finally, the Torah tells us that those who witnessed the ground swallowing the group fled “LeKolam,” “To their voices” (16:4). Most classical commentators explain this strange phrase to mean that Bnei Yisrael fled away from the voices of Korach’s men. In a similar vein, Rashbam explains this to mean that they ran from the sound of the earth trembling. Iturei Torah quotes Rav Chanoch of Alexander who, in a more homiletical explanation, suggests that Bnei Yisrael ran to the “voice” of prayer with which Yitzchak had blessed Yaakov. When they saw the terrible punishment being inflicted upon Korach’s group, they prayed that they themselves be spared.
Sefer Al HaTorah explains that Bnei Yisrael were teetering back and forth between Moshe and Aharon on one hand and Korach on the other. When Korach and his group were swallowed up, Bnei Yisrael went running to find the reassuring voices of Moshe and Aharon. On the other hand, Targum Yonatan elucidates that Korach and his group screamed from below, “Hashem is righteous and the words of Moshe, His servant, are true. We are wrong.”
Based on this suggestion of the Targum Yonatan, we can understand a comment by Rav Reuven Margalios, cited in Iturei Torah. Rav Margalios observes that Moshe did a great kindness to the rebels by allowing them to be swallowed up alive, thereby affording them the opportunity to do Teshuva. According to Targum Yonatan, Korach and his fellows in fact did Teshuva by acknowledging their sin. We see the tremendous trait of kindness Moshe had. He gave those who sought to depose him the opportunity to do Teshuva. We should not be implacable and unforgiving, but should rather learn from Moshe to always allow those who have wronged us to repent.