The Erev Rav (mixed multitude)
"Before the coming of the Mashiach most of the Rabbanim will be from the Erev Rav etc. Because Israel in themselves are holy, but the Erev Rav work only for their own benefit as we can clearly see that the Rabbanim and the Chassidim and many regular Jews of the generation are, due to our many sins, mostly from the Erev Rav and want to rule over the public, and all their actions are only for their own sake, to acquire honor and money, and one should therefore only join with those who truly serve, who sacrifice themselves to Hashem not in order to receive any benefit". (Divrei Chaim, Parshas Vayakhel)In the Tikkune Zohar (97a) it is written: "All the exile and the destruction of the Beit ha Mikdash and all the suffering, all of it came through Moshe's acceptance of the Erev Rav, and all wicked people and evildoers in each generation come from them, meaning from their souls, for they are reincarnations of those who left Egypt and this is what the Gemara (Beitza 32) refers to: "They come from the Erev Rav".
"The Erev Rav delay the redemption much more than all the nations of the World" (Raaya Mehemna-Sefer Ha Zohar)
The root of our deficiency comes from what the Erev Rav do to us. As it is written in the Zohar: "They (The Erev Rav) damage Israel more than all the nations". And one has to strengthen oneself with great faith (EMUNA), because Israel were redeemed from Mitzrayim only in the merit of faith, and so it will be with the future redemption, that we will need great faith because we will see how the ways of evildoers succeed. and even if we see in them (The Erev Rav) good things like Torah and tradition and good manners and in particular they make peace with everybody and peace is the foundation of everything, and it is a very good trait, even so, as in the case of a sick person that needs to have his blood extracted even though the soul is in the blood, so it will be in the days prior to Mashiach, we must reject all these people even when they have good aspects in their behavior because then will be time of Clarification and selection and this will be the trial and choice in those days (Divre Simcha by Rabbi Simcha Ysachar Ber Chalberstam, zt'l).
In "Bnei Yisachar" (articles of Chodesh Adar) it is written, "the groups of the Erev Rav who sit among us, are heretics, informers, Apikorsim, they are from the root of Amalek, the Sitra Achra, (Erev Rav in Gematria = Sitra Achra) as you may see in these generations, that on account of our myriad sins, the heresy has increased. And there are those who carry weapons on them to wound Israel with bad advice and faulty laws." And in the Zohar Chai Parashat Bereshit (4, pg. 96) it says: "And the Erev Rav is the bad side of Moshe, and Moshe wanted to correct them. And Moshe himself comes in every generation (in the ARIZAL, afterwards in the BAAL SHEM TOV) and he will reincarnate in the last generation among the Erev Rav. And now most of the generation with their leaders are from the Erev Rav. And Moshe comes to prevent the Erev Rav from derailing the people of Israel".
My Holy master the Baal Shem Tov explained the argument of the Yetzer ha Ra [SAMA'EL] when a holy soul comes down to this world in order to invest itself in a body, The Yetzer says to Hashem: "You have created me in vain" for this Tzaddik that is coming into the world will turn many people in teshuvah and will bring them closer to Hashem therefore fixing the world through great faith and Torah and Tefillah, and me I am an angel a spiritual being that can't be seen and he the Tzaddik is in a physical body and will lead the people in good ways with fear and love and who will listen to me? And the answer came to the Satan: "All men" for as a counter balance for every real Tzaddik there is another one who opposes him, who possesses no love and fear of G-d, but only confuses creatures. He looks as a Tzaddik and guides the people to different kinds of wisdom and strange beliefs and he has great strength and from this comes the free will [that people will have to choose between good and evil] and this is "All men" that though a man one can go to the right place or to the wrong place. (Zohar Chai, Bereshit 329)
Moses will arise again, meaning that he will be reincarnated in the last generation, and so will the Mixed Multitude...the generation of the desert will also return and be reincarnated in our, last generation.
