This is in keeping with Benjamin's image throughout the Torah. Joseph is reconciled with the Judah and his brothers by their shared desire to protect young Benjamin. As for the tribe, we see the first hint of its unifying force in this week's Torah portion, Tetzaveh, as interpreted by the Jerusalem Talmud. The Torah states that the High Priest (I'd prefer Prime Minister, but whatever) wears an onyx on each shoulder of his vestments:
Take two onyx stones and engrave on them the names of the sons of Israel in the order of their birth—six of their names on one stone and the names of the remaining six on the other.The Jerusalem Talmud (Sota 7:4) states:
Said Rabbi Johanan: "Benjamin was split: 'Ben' on one and 'Jamin' on the other."So Benjamin is quite literally the uniter; you need to put the two stones together to read his name. This is true not only in rocks, but in dirt as well: once the Israelites cross the Jordan, Benjamin receives the critical territory in the center of the country, bridging Judah in the south, Joseph in the north, Gad in the east and Dan in the west.
Said Rabbi Zebida: "Indeed! Does it say: their six names? No, it says, 'six of their names'--part of their names, not all of their names."
In fact, Saul is neither the first nor the last of the wolf pack to unite the tribes. The period of the Judges begins in earnest with Benjamite Ehud ben Gera and his successor Shamgar ben Anat, ushering in an unequaled eighty-year Pax Judicia. Similarly, the post-exilic period is ushered in by Benjamites Mordecai and Esther (whose family tree shares many names with Saul's), who institute Purim, a new holiday to be celebrated, quite literally, by Jews far and near. In fact, Mordecai is the first person to be labelled "the Jew" even though his paternal line does not go back to Judah.
Thus, we see that Benjamin symbolizes unity and unification. The lone son of Jacob to be born in the Holy Land, the lone son to be innocent of sin in the Joseph episode (as well as any other wrongdoing, according to Talmud Shabbat 55b) fathers the tribe which creates the United Kingdom of Israel and later sticks with Judah when the Ten Tribes split off.
That's what makes the episode of the Concubine of Gibeah so shocking. The Book of Judges ends with the story of this brutal gang rape and murder. The Israelites want the perpetrators, from the Benjamite town of Gibeah, to be brought to justice (Jud. 20:11-14):
So all the men of Israel gathered together at the city as allies. The tribes of Israel sent men throughout the tribe of Benjamin, saying, “How could such a wicked thing take place? Now, hand over the miscreants in Gibeah so we can execute them and purge Israel of wickedness.” But the Benjamites refused to listen to their Israelite brothers. The Benjamites came from their cities and assembled at Gibeah to make war against the Israelites.Benjamin is a unifying force here as well, but not for good. They go from being a tribe of Israel to an enemy of Israel, all in the name of sticking up for Gibeah. In the ensuing civil war, tens of thousands are killed on both sides, and Benjamin is almost exterminated.
This shows us the limits of ahdut, unity. Yes, the Jewish people have survived for millennia by sticking together. However, that value cannot undermine our basic commitment to justice. Clearly, the Benjamites of Judges 20 thought that the abuse of one woman was a trifling issue, to be ignored for the good of the whole. But covering up episodes of sexual violence does not preserve a society; it rots it from within. Justice, even for one individual, is the concern of the entire society. Without it, what is the purpose of a nation's survival at all?