"Ben Poras Yosef, Ben Poras Alei Ayin." (Vayechi 49:22) Rashi says that this means that Yosef will multiply and be beyond the reach of Ayin Hara. As a reward for not taking his master's wife, no one will be able, through jealously, to inflict any harm on what belongs to him.
The Shulchan Gavo'a brings
from Rav Eliyahu Dessler, that no matter how rich a person is, no one is ever
jealous of a totally selfless person whose whole life is about giving. An
element of jealousy stems from the intended or even unintended flaunting of
oneself before others.
Yaakov gave Ephraim and Menashe a bracha,
"V'Yidgu LaRov; They should multiply like fish." There are two attributes of
fish that Yaakov had in mind. Fish are not seen from the dry land. Moreover
the fish live a life totally separated from the inhabitants of the land. They
don't compete with them in any way. That is why the Ayin Hara does not affect
If a person lives a life of Yosef, where he doesn't want what
doesn't belong to him, and he lives and enjoys his material assets out of the
public eye, he, too, will not suffer from any unwanted evil eyes.