ויבאו [וַיָּבֹ֣א] רְחַבְעָם֮ יְרוּשָׁלִַם֒ וַיַּקְהֵל֩ אֶת־כָּל־בֵּ֨ית יְהוּדָ֜ה וְאֶת־שֵׁ֣בֶט בִּנְיָמִ֗ן מֵאָ֨ה וּשְׁמֹנִ֥ים אֶ֛לֶף בָּח֖וּר עֹשֵׂ֣ה מִלְחָמָ֑ה לְהִלָּחֵם֙ עִם־בֵּ֣ית יִשְׂרָאֵ֔ל לְהָשִׁיב֙ אֶת־הַמְּלוּכָ֔ה לִרְחַבְעָ֖ם בֶּן־שְׁלֹמֹֽה׃ (פ)
At nang dumating si Rehoboam sa Jerusalem, tinipon niya ang buong sambahayan ng Juda at ang lipi ng Benjamin, isandaan at walumpung libong piling lalaking mandirigma, upang makipagdigma laban sa sambahayan ng Israel, upang maibalik ang kaharian kay Rehoboam na anak ni Solomon.
Rashi
And the tribe of Binyomin. Who were situated on the border, because the boundaries of Yehudah and Binyomin were adjacent.