Verse 17 lists the sons of Reuel as his clan descendants. We may restructure this also to say, for example, “The ancestor of the clans called Nahath, Zera, Shammah, and Mizzah was Reuel. Reuel’s father was Esau, and his mother was Basemath.”

Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Genesis. (UBS Helps for Translators). New York: UBS, 1997. For this and other handbooks for translators see here .