The Berachot that Yaakov gave his children can all be interpreted to show the development of that son and the tribe they father. The most interesting of the Berachot is the one given to both Shimon and Levi. The Beracha is as follows: “Shimon and Levi are brothers; weapons of violence are their swords. Into their conspiracy do not bring my soul, my honor shall not become one with their congregation; for in anger they killed a man, and because they desired it they maimed an ox. Cursed be their anger for it is fierce, and their wrath because it is cruel; I will divide them within Jacob, and I will disperse them within Israel” (49:5-7). Let us see what the Beracha means.
“Shimon and Levi are brothers.” They act together towards those they feel have wronged them. For this reason Yosef put Shimon in prison when the other brothers went back up to get Binyamin: leaving Shimon and Levi together posed a threat. The Midrash states that although they acted as brothers towards Dina in Shechem, they did not act like brothers towards Yosef when he was being sold to the Yishmaelim.
“Weapons of violence are their swords.” This might refer to the killing of Kazbi and Zimri, which was done by Pinchas, a descendant of Levi. Zimri was in fact from the tribe of Shimon (see Rashi to 49:6). Pinchas killed Kazbi and Zimri due to his zealousness and love for Hashem. This suggests that Levi had killed Shechem for true intentions of love towards his sister, whereas Shimon did so out of a desire for war. Thus, in the Pasuk regarding Dina, “Each man took his sword” (34:25), one can explain that Shimon took his sword for destroying Shechem and Levi took his sword for saving Dina. This idea can also be supported from Rashi, who states that Shimon and Levi had a thrill for destruction that they got from their uncle, Esav.
This is where the brotherhood part of the Beracha ends. The rest of the blessing is a set of parallels, one side applying to Shimon and one side applying to Levi. (The Netziv’s approach is contrary to this author’s, in that the only similarity between Shimon and Levi was the sword; other comments made by the Netziv in this place appear to be similar to this author’s. See Netziv’s commentary to 49:5. Also, see Rav Yuval Sherlow’s essay in Alon Shevut 100, where a similar idea is expressed.)
“Do not bring my soul into their conspiracy.” This refers to Shimon. Since Shimon’s intentions in the Shechem episode were not pure, Yaakov did not want to have any part of it. Kazbi who worshipped Baal and sinned with a Midianite woman, also fits, as the Pasuk says that Midianim “shall not be brought (Lo Yavo) into Hashem’s nation,” and here the language is, “do not bring (Al Tavo) my soul into their conspiracy.”
“My honor shall not become one with their congregation (Kahalam).” The use of the word Kahalam is similar to that used by Korach, a descendant of Levi “Kahalu Al Moshe,” “and they gathered against Moshe” (Bemidbar 16:3). The idea is that Hashem will not become part of a congregation that rebels. Rashi’s comments are similar. However, this applies only to that section of the sons of Levi who try to make themselves even more distinct. For that reason it says “their congregation” and it does not say “them.”
“In anger they have killed a man.” It is hard to know if this verse was said referring to Shechem, for there they killed the entire town and not simply one man. However, assuming it is referring to Shechem, it might be explained by the Pasuk in that episode that says they specifically killed Chamor and Shechem, individually, by sword (34:26). This can be compared to how Bilam was killed (Bemidbar Sinai 31:8).
“And because they desired it they maimed an ox.” This can be referring to either of the cases we have been discussing: Shechem or Midian. If this verse is referring to the sons of Levi, it could also be referring to Korbanot. This is the first time we see a radical change in our perception of Shimon and Levi, not only with regard to intent but a completely separate action. (Rashi’s comments are that the ox refers to Yosef, who they tried to “maim.” However, this is unsatisfying, as the Pasuk says that they successfully maimed the ox.)
“Cursed be their anger for it is fierce.” This refers to Shimon who did not stop at killing only Shechem and Chamor but destroyed the entire city. (However one will note that given the circumstance, and the goal of not selling their sisters as Harlots, it was necasary for them to kill the entire town.)
“And their wrath because it is cruel.” This refers to Levi. The Gemara states that it is commonly known that Kohanim in particular have short tempers. There are stories about the Chafetz Chaim’s having to train himself not to get angry. We see that Pinchas used this trait positively. However, their wrath is cruel both to those who are the receivers of the wrath and to the Kohanim who get very angry. It is cruel to others because they should not be victims of the wrath, and it is cruel to them because it is very challenging to control it.
“I will divide them within Jacob.” This is refers to Shimon, whose portion of land was “swallowed up” by that of Yehuda because Yehuda’s portion was so large next to Shimon’s, which was very small (Yehoshua 19:1,9). The word divide is of the same root as the word portion. Jacob here refers to Yehuda, as the Midrash states that Yaakov’s descendants will not be known as sons of Reuven, rather as sons of Yehuda (Yehudim).
“I will disperse them within Israel.” This refers to the Leviim, who were the center of the camp in the desert. Their job was always at the center of the rest of the tribes. In Eretz Yisrael they worked in Yerushalayim, which is the center of the land. However, their actual territory was in various cities dispersed across the land (Yehoshua 21:1-3).
Ultimately, Shimon was the first tribe to be lost, while the tribe of Levi is still identifiable today. We see that when two people do the same action one can be rewarded for doing a Mitzva while the other is punished for sinning. The Gemara states that being born under certain stars will orient your personality. However, one can use that orientation for good or for bad. One who born under a violent sign can either become a Shochet like Levi or a killer like Shimon.