Know Your Capabilities

From The Mir Parsha Sheet with slight editing

Yaakov puts his right hand on Ephraim, the younger of Yosef's sons because he foresaw that his descendants would be greater for Yehoushua would come from him.  However, why did Yaakov then not give the greater beracha to Menasha to give him the ability to have greatness emerge from him?  Says R' Yerucham Levovitz, we see that a  berachah does not  change the person’s capabilities, but helps one bring out their own capabilities.  Menasha did not have the same potential as Ephraim and Yaakov could not make that appear through a beracha.  

The possuk says כָּל אֵלֶּה שִׁבְטֵי יִשְׂרָאֵל שְׁנֵים עָשָׂר וְזֹאת אֲשֶׁר דִּבֶּר לָהֶם אֲבִיהֶם וַיְבָרֶךְ אוֹתָם אִישׁ אֲשֶׁר כְּבִרְכָתוֹ בֵּרַךְ אֹתָם and Rashi notes that he gave berachos to them all. Yet it doesn’t seem as though he actually blessed all of them. Reuven, he rebuked, and when addressing Shimon and Levi, he cursed their wrath — אָרוּר אַפָּם כִּי עָז וְעֶבְרָתָם כִּי קָשָׁתָה, and declared that they should be dispersed among Klal Yisrael: אֲחַלְּקֵם בְּיַעֲקֹב וַאֲפִיצֵם בְּיִשְׂרָאֵל. This does not sound like a beracha!  How, then, can the Torah say that he blessed all his sons? R' Yerucham explains that giving a berachah means helping a person identify and utilize the dormant kochos that Hashem implanted in his nature.   As the Rashba (cited in Nefesh HaChaim shaar 2) notes the word ברכה comes from the word בריכה, a spring that gushes forth.  A beracha brings forth potential power that it stored away.  The berachot Yaakov gave were to help bring forth the natural abilities, talents and capabilities of the brothers.  That was the berachah that Yaakov gave his sons. To Reuven, he pointed out that his nature was to be hasty, so he had to be careful to channel that impulsivity properly. To Shimon and Levi, he said, You have this middah of kaas, and you have to know how to use it, so that it shouldn’t drag you down. To Yehudah, he gave a berachah that he should realize that he possesses the capacity to admit, which is the quality of a king.

The greatest berachah, then, is to know your kochos.