Yaakov does not speak of any specific event, but rather about the brothers' extreme wrath and violent nature. This position subdivides regarding how it thinks Yaakov evaluates these traits:
Yaakov views the brothers uncontrollable rage negatively, and by Yaakov points to it as the reason that neither Shimon nor Levi merit kingship.
Blessings - on the past or future – According to R"Y Bekhor Shor, much of Yaakov's final address to his sons relates to their roles during the Monarchic period. Thus, he opens his words, by telling Shimon and Levi why they did not merit to inherit the monarchy and right to rule, but were instead dispersed throughout the tribes.
"כְּלֵי חָמָס מְכֵרֹתֵיהֶם" – R"Y Bekhor Shor asserts that the word "מְכֵרֹתֵיהֶם" is related to the root "מכר", meaning acquaintance. Yaakov tells the brothers that their relationship is a weapon of violence. It is not clear what R"Y Bekhor Shor means by this. He might be suggesting that the common denominator between the brothers is their quick temper. Alternatively he is suggesting that the friendship between the brothers was prone to lead to violence due to the hot-hotheadedness of each.
"בְּסֹדָם אַל תָּבֹא נַפְשִׁי בִּקְהָלָם אַל תֵּחַד כְּבֹדִי" – According to R"Y Bekhor Shor, when Yaakov says "נַפְשִׁי" and "כְּבֹדִי" he is not referring to himself, but to his descendants, Yaakov expresses that he has no desire that his other sons be a part of Shimon and Levi's secret machinations, or be led by them at all, since their wrath is likely to lead to evil.
"כִּי בְאַפָּם הָרְגוּ אִישׁ וּבִרְצֹנָם עִקְּרוּ שׁוֹר" – This verse is not referring to any specific deed, but the brothers' general tendency to kill in their anger, and to hamstring oxen even when not angry (בִרְצֹנָם).
"אָרוּר אַפָּם כִּי עָז" – Blessing or curse? R"Y Bekhor Shor understand Yaakov's words as a condemnation of the brothers anger, which led them to lose out on kingship. They are dispersed among Israel so as to be separated from one another, preventing them from consulting together in their anger.
No mention of Shekhem – According to this approach, Yaakov might have the episode of Shekhem in mind as he spoke but chose not to bring it as an example because, of all their wrathful deeds, it might have been the most justified.
No mention of Yosef – R"Y Bekhor Shor might not think that Shimon and Levi's role in the sale of Yosef (and original plan to kill him) was any different than that of the rest of the brothers. If so, even if Yaakov was aware of the episode, he had no reason to chastise them more than anyone else.
Yaakov finds the brothers' anger and willingness to kill praiseworthy and a necessary trait for the nation, as it provokes fear in Isarel's enemies. Yaakov saw that the brothers would ensure that there was always someone who could fight Israel's battles.
Praise or rebuke – R. Yehuda HeChasid is unique in understanding Yaakov to be praising rather than rebuking Shimon and Levi, seeing in their anger and readiness to kill a necessary and meritorious quality.
24 "כְּלֵי חָמָס מְכֵרֹתֵיהֶם" – R. Yehuda HeChasid raises two possible understandings of the word "מְכֵרֹתֵיהֶם". It might mean weapon, being related to the Greek word for knife, "מכיר". Alternatively, it could refer to a "dwelling," in which case Yaakov is saying that the brothers will employ violence against their enemies in the land of their dwelling. Either way, Yaakov is praising Shimon and Levi's readiness to fight.
"בְּסֹדָם אַל תָּבֹא נַפְשִׁי בִּקְהָלָם אַל תֵּחַד כְּבֹדִי" – According to R. Yehuda HeChasid this represents the speech of Israel's enemies (or their mercenaries) who lie in fear of Shimon and Levi and have no desire to take part in a war in which they will be present.
"כִּי בְאַפָּם הָרְגוּ אִישׁ וּבִרְצֹנָם עִקְּרוּ שׁוֹר" – Yaakov points out how quick the brothers are to kill, sharing how they do not even take booty, but instead kill the animals to show how capable they are. This attitude led to the fear of surrounding nations.
"אָרוּר אַפָּם כִּי עָז וְעֶבְרָתָם כִּי קָשָׁתָה" – This sentence, too, represents the words of enemy nations, who recognize the harsh wrath of Shimon and Levi and fear them as a result.
"אֲחַלְּקֵם בְּיַעֲקֹב וַאֲפִיצֵם בְּיִשְׂרָאֵל" – R. Yehuda HeChasid asserts that Yaakov is referring to the fact that all the other tribes will desire to hire Shimon and Levi to fight for them.
25 They will be divided among Israel as they spread out to fight for each tribe.
26 No mention of Shekhem – This approach might assume that the incident in Shekhem was one of the reasons that the brothers had the reputation that they did. If so, in Chapter 34 Yaakov had not been upset about the extremity of the the brothers' actions, only worried about the prudence of the deed.The fact that the Torah gives the last word to the brothers there (their cry, "") might suggest that Hashem, too, had no issue with the brothers' deed, recognizing that certain crimes call for extreme reactions.
No mention of sale – According to R. Yehuda HaChasid, though the brothers planned to sell Yosef, they never did so as the Midianites beat them to it. Shadal's cousin goes a step further to suggest that the brothers themselves were unaware of the sale and astonished when Reuven found the pit empty, leading them to conclude that Yosef had indeed been killed by a wild animal (as they told their father). [See
Who Sold Yosef for details.] If so, it is very likely that Yaakov never learned of the original plotting,
27 and clear why he does not rebuke Shimon and Levi for the sale.
28 Motivation