וַיָּמָת֮ בַּ֣עַל חָנָ֣ן בֶּן־עַכְבּוֹר֒ וַיִּמְלֹ֤ךְ תַּחְתָּיו֙ הֲדַ֔ר וְשֵׁ֥ם עִיר֖וֹ פָּ֑עוּ וְשֵׁ֨ם אִשְׁתּ֤וֹ מְהֵֽיטַבְאֵל֙ בַּת־מַטְרֵ֔ד בַּ֖ת מֵ֥י זָהָֽב׃
And Baal-hanan the son of Achbor died, and Hadar reigned in his stead; and the name of the city was Pau; and his wife’s name was Mehetabel, the daughter of Matred, the daughter of Me-zahab.
Rashi on Genesis
בת מי זהב THE DAUGHTER OF ME-ZAHAB — meaning מהו זהב what value has gold? He was so rich that gold had no value in his eyes (Genesis Rabbah 83:4).
Radak on Genesis
וימלוך תחתיו הדר...ושם אשתו וגו', we do not know why both his wife’s name and that of her father have been mentioned.