דברי הימים א, פרק ד׳, פסוק ח׳

Tracing family lineages often involves putting together pieces of a historical puzzle, especially when a sudden new name appears without a clear background. The unexpected introduction of Koz into the genealogical record, without any prior mention or explicit connection to a parent, creates a mystery regarding his identity [ביאור שטיינזלץ].

This lack of clarity leads to two primary ways of understanding his place in the family tree. One perspective suggests that Koz is another son of Helah, a woman mentioned just prior in the lineage. Following this view, Koz became the father of Anub and Zobebah, and also established the families of Aharhel. Therefore, all these subsequent generations are ultimately the descendants of Helah [רלב״ג, מלבי״ם]. On the other hand, a different approach views Koz not as a new, unlinked individual, but rather as someone who was already listed earlier in the records under a completely different name. The sudden appearance of figures without a clear introduction to their identity or ancestry is a recognized pattern throughout the book of Chronicles [מצודת דוד].