וּרְאָיָ֤ה בֶן־שׁוֹבָל֙ הוֹלִ֣יד אֶת־יַ֔חַת וְיַ֣חַת הֹלִ֔יד אֶת־אֲחוּמַ֖י וְאֶת־לָ֑הַד אֵ֖לֶּה מִשְׁפְּח֥וֹת הַצָּֽרְעָתִֽי׃ (ס)
און רְאָיָה דער זון פֿון שוֹבֿלן האָט געבאָרן יַחתן, און יַחת האָט געבאָרן אַחומַין, און לַהַדן. דאָס זײַנען די משפּחות פֿון די צָרעָתים.
Rashi
And Reaiah This is the manner in which this genealogy [is written]; although Reaiah, [and his father] were not enumerated above, [he is mentioned here] because the Chronicler reckons [only] certain generations. Likewise, (vs. 7f.): “And the sons of Helah: Zereth, and Zohar, and Ethnan. And Koz begot...” Although he did not yet mention Koz, he mentions his sons.