שמות, פרק ו׳, פסוק כ״א

Genealogies in the biblical narrative are rarely just dry lists of names. Instead, they act as a guide for the future, carefully introducing the individuals who will shape the events to come. The primary approach among commentators is that the specific listing of Izhar's sons is designed first and foremost to introduce Korah. He is placed in the record now because he will eventually become a problematic figure, leading a rebellion against Moses and Aaron while the Israelites wander in the desert. Because Korah needs to be introduced for this future narrative, his brothers, Nepheg and Zichri, are included alongside him.

This focus on future events explains the selective nature of the family trees presented for the tribe of Levi. The record details the descendants of Amram, Izhar, and Uzziel, while intentionally skipping the children of Gershon, Merari, and Hebron. Only the families that produce key players for upcoming historical moments are recorded. This includes Moses and Aaron, the rebellious Korah, and Mishael and Elzaphan, who will later be involved in the events surrounding the deaths of Nadab and Abihu.

Individuals who do not play a role in significant future events are simply left out of the record. However, there is another perspective regarding the missing names. According to [דעת זקנים], the families whose descendants are not listed, such as the family of Hebron, were omitted for a much simpler reason: they simply did not have any sons.