וַיֹּ֣אמֶר מֹשֶׁ֔ה לִבְנֵי־גָ֖ד וְלִבְנֵ֣י רְאוּבֵ֑ן הַאַֽחֵיכֶ֗ם יָבֹ֙אוּ֙ לַמִּלְחָמָ֔ה וְאַתֶּ֖ם תֵּ֥שְׁבוּ פֹֽה׃
And Moses said unto the children of Gad and to the children of Reuben: ‘Shall your brethren go to the war, and shall ye sit here?
Read midrashic interpretation of Numbers 32:6: and classical rabbinic exegesis.