Wlastow G.K.
Reuben led the southern division of the camp, displaying a significant banner. Traditionally, the standard representing this southern front was red. Adorning Reuben's prominent crimson flag was the image of an eagle.
In the camp of the sons of Ruben, on the south side, the prince shall be Elisur the son of Sedeur:
דֶּ֣גֶל מַחֲנֵ֧ה רְאוּבֵ֛ן תֵּימָ֖נָה לְצִבְאֹתָ֑ם וְנָשִׂיא֙ לִבְנֵ֣י רְאוּבֵ֔ן אֱלִיצ֖וּר בֶּן־שְׁדֵיאֽוּר׃
One Church Father comments on this verse
Reuben led the southern division of the camp, displaying a significant banner. Traditionally, the standard representing this southern front was red. Adorning Reuben's prominent crimson flag was the image of an eagle.
Passages read together with this verse.