I Chronicles 2:27 Midrash

וַיִּהְי֥וּ בְנֵי־רָ֖ם בְּכ֣וֹר יְרַחְמְאֵ֑ל מַ֥עַץ וְיָמִ֖ין וָעֵֽקֶר׃

And the sons of Ram the first-born of Jerahmeel were Maaz, and Jamin, and Eker.

Read midrashic interpretation of I Chronicles 2:27: and classical rabbinic exegesis.