I Chronicles 1:23 Midrash

וְאֶת־אוֹפִ֥יר וְאֶת־חֲוִילָ֖ה וְאֶת־יוֹבָ֑ב כָּל־אֵ֖לֶּה בְּנֵ֥י יָקְטָֽן׃ (ס)

and Ophir, and Havilah, and Jobab. All these were the sons of Joktan.

Read midrashic interpretation of I Chronicles 1:23: and classical rabbinic exegesis.