In this week's Parsha, the Torah teaches us about Yaakov blessing Ephraim and Menasheh. The text of this blessing includes the phrase, "בך יברך ישראל לאמור ישימך אלוקים כאפרים וכמנשה" meaning that the Jewish people shall use you in a blessing, saying, "Hashem should make you like Ephraim and Menasheh" (בראשית מ"ח:כ'). Rashi here comments that when Jewish parents come to bless their sons, they will say ישימך" אלוקים כאפרים וכמנשה" as the text of their blessing.
Why should Yaakov have wanted future generations to bless their children that they should be specifically like Ephraim and Menasheh, the children of Yosef, rather than like one of the actual twelve tribes? The מעינה של תורה ספר, Wellsprings of Torah, quotes an answer from Rabbi Hirch Melech Dinnover. The conduct of Ephraim and Menasheh shows that a person shouldn't consider himself superior to anyone else, nor should one be envious of anyone else. Even though Yaakov had given precedence to Ephraim, the younger son, over Menasheh, the Bechor, Ephraim still didn't become arrogant based on his status, and Menasheh didn't become jealous. Seeing this, Yaakov expressed the hope that all of the Jewish people would emulate Ephraim and Menasheh and be free of both arrogance and envy.
This concept is elaborated upon in Pirkei Avos (פרק ד' משנה כ"ח). Rabbi Elazar Hakappar teaches that הקנאה ובתאוה ובכבוד מוציאין את האדם מן העולם, jealousy, lust, and seeking honor remove a person prematurely from this world. Menasheh's attitude teaches us to avoid jealousy of another person's success while Ephraim's attitude teaches us how to avoid seeking honor even when one has received it. Elsewhere in Pirkei Avos (פרק ג' משנה י"ח), Rabbi Akiva says חביב אדם שנברא בצלם אלקים, man is beloved because he was created in the image of Hashem. No person, therefore, should be envious of another, because he too has this צלם אלקים himself. At the same time, nobody should look down on another person because that person too has this צלם אלקים.
We must take this message to heart and incorporate it into our lifestyles so we can fulfill this hope of Yaakov Avinu that his descendants will learn to stay away from desiring what other people possess and from looking down at other people.