What does the fact that only a thousand warriors from each tribe were sent to war teach us?
The Torah does not explicitly explain why exactly a thousand from each tribe were chosen, and so the following are interpretive ideas that emerge from the structure of the story.
First, the war is not presented as the mission of a particular tribe, but of the whole people of Israel. The command stresses:
“A thousand from each tribe, a thousand from each tribe, from all the tribes of Israel you shall send to the army.” (Numbers 31:4)
Every tribe sends the same number of warriors. The large tribe does not send more, and the strong one does not receive center stage. This may teach that the campaign against Midian is regarded as a shared responsibility: every tribe carries an equal share in the pain, the memory, and the repair.
Second, twelve thousand is a relatively small force compared to a nation of more than six hundred thousand men of military age. This is an interpretive idea: perhaps the Torah wishes that we not attribute the victory to numerical strength alone. The army is limited, but the mission is clear, and alongside it goes Pinchas with the holy vessels and the trumpets of the alarm.
And here a particularly surprising detail appears: at the end of the war the officers of the army report that not a single warrior was lost:
“And not a man of us is missing.” (Numbers 31:49)
One can read the story like this: the Torah sends a limited and precise force, from each tribe equally, and then tells that they all returned. It was not an anonymous crowd that went to battle, but twelve parts of one people, and no part vanished.
And there is a further insight here: perhaps the words “a thousand from each tribe” are not only a military instruction, but a picture of unity. Each tribe keeps its own identity, but at the moment of truth they all gather into one army.
In one sentence:
The victory over Midian is not a story about the strongest tribe, but about a people in which every tribe sends a part of itself, and all bear the same mission together.
More questions and answers on Parashat Matot: