אֶת־ע֥וּץ בְּכֹר֖וֹ וְאֶת־בּ֣וּז אָחִ֑יו וְאֶת־קְמוּאֵ֖ל אֲבִ֥י אֲרָֽם׃
si Uz na kanyang panganay, at si Buz na kanyang kapatid, at si Kemuel na ama ni Aram;
Da'at Zekenim
את עוץ בכורו, “his firstborn son Utz, etc.; according to B’reshit rabbah this is a reference to Job (Job, 1,1) where we are told about Job living in the land of Utz.
Radak
את עוץ בכורו, as we explained already on Genesis 10,15 in connection with the phrase את צידון בכורו.
Tur HaArokh
קמואל אבי ארם. According to Nachmanides, Aram is mentioned in order to have an excuse to mention Kemuel, to show that Kemuel’s son Aram became far more distinguished than his father. [normally, the Torah lists the names of people as “son of such and such.” The reverse here indicates that the son outshone the father. Ed.]