Rashi and Targum Yonasan: They wanted to stress that he died for his own personal sin and not for that of Korach, who stirred-up the people against Hashem, or for that of the Mislon'nim, who caused others to sin (or the sin of the Meraglim, who rebelled against Hashem). ¹

Ramban #1, Seforno and Moshav Zekenim #1: They were pointing out that he was not in Korach's congregation or the complainers in his congregation, ² who lost their portion in Eretz Yisrael ? and that they were therefore permitted to inherit his property.

Ramban #2 and Moshav Zekenim #2: They assumed that Moshe hated Korach and his congregation more than all the other sinners who died in the desert because they set out to attack him and to negate everything that he had accomplished, and that he would therefore pray that 'he should have no-one who extends him kindness and that no-one should show his orphans mercy, and that the sins of his father be remembered before Hashem'. ³ And they added that he died of his own sin to explain why he died in the desert and did not merit to enter Eretz Yisrael, or they were explaining why he left behind no sons. ⁴

Bava Basra, 118b: "be'Soch ha'Eidah" refers to the Meraglim; "ha'No'adim al Hashem", to the Mis'on'nim - who grumbled after they left Har Sinai and ?ba?Adas Korach?, to the rebellion of Korach.

Refer to 27:3:1:1-3.

Rashi #1 (citing R. Akiva Shabbos, 96b): Because he collected wood on Shabbos. ¹

Rashi #2 (citing R. Shimon ² in Shabbos, 96b): Because he was one of the Ma'apilim. ³

Bava Basra, 119b: It teaches us that the B?nos Tz?lofchad were ?Darshaniyos? (clever) who know that if their father would have had sons, they would not have had a keg to stand on. ¹