וַיֹּ֣אמֶר יְהוּדָה֩ לְשִׁמְע֨וֹן אָחִ֜יו עֲלֵ֧ה אִתִּ֣י בְגוֹרָלִ֗י וְנִֽלָּחֲמָה֙ בַּֽכְּנַעֲנִ֔י וְהָלַכְתִּ֧י גַם־אֲנִ֛י אִתְּךָ֖ בְּגוֹרָלֶ֑ךָ וַיֵּ֥לֶךְ אִתּ֖וֹ שִׁמְעֽוֹן׃
Sinabi ng Juda kay Simeon na kanyang kapatid: “Umakyat ka kasama ko sa aking bahaging lupain, at makipagdigma tayo laban sa mga Cananeo; at sasama rin ako sa iyo sa iyong bahaging lupain.” Kaya sumama sa kanya si Simeon.
Midrash Aggadah
To Shimon, Shelumiel ben Tzurishaddai. Even though his descendant is Zimri, on whose account 24,000 died in a plague, G-d made peace with him and placed him next to Reuben, who had done repentance (a ba'al t'shuvah). Therefore it is said, "ben tzuri-shaddai," ("Shaddai is my rock")...
Sifrei Devarim
"And to his people shall You bring him": For he (Judah) had drawn him (Shimon) near to himself for inheritance (of the land), as it is written (Judges 1:3) "and Judah said to Shimon his brother: "Go up with me (in battle) for my portion." And sections fell (for inheritance) from the inheritance of the children of Judah to that of the children of Shimon (viz. Joshua 19:9).