Комментарий к Шмот 6:21

ובני יצהר, “and the sons of Yitzhar;” why did the Torah list the sons of Amram and the sons of Yitzhar as well as the sons of Uzziel, who were great-grandchildren of Kehat, while not listing the descendants of either Gershon or Merari, nor did it list the descendants of Chevron who were related in a similar degree? We may have to answer that the descendants of Amram who included Moses and Aaron, were important, and similarly the descendants of Yitzhor who included Korach were important, and Uzziel was important as his sons Mishael and Elitzafan brought Nadav and Avihu to burial, so that his sons are mentioned here also. (Compare Leviticus chapter 10)