וְנָסַ֗ע דֶּ֛גֶל מַחֲנֵ֥ה רְאוּבֵ֖ן לְצִבְאֹתָ֑ם וְעַל־צְבָא֔וֹ אֱלִיצ֖וּר בֶּן־שְׁדֵיאֽוּר׃
And the standard of the camp of Reuben set forward according to their hosts; and over his host was Elizur the son of Shedeur.
Read midrashic interpretation of Numbers 10:18: and classical rabbinic exegesis.