Hassidout sur La Genèse 46:4

Genesis 46,4. “I will descend to Egyt with you, and I ‎will also ascend with you.” In order to understand this ‎verse properly, we must remember the pedagogic rule that when ‎a teacher is confronted with a student of limited intellect, he ‎must endeavour to rein in his superior intellect and descend to ‎the level of the student. When faced with a student who has a ‎brilliant mind, the teacher need not impose any restrictions on ‎himself when teaching such a student. As long as Yaakov resided ‎in the Holy Land, his intellect was very strong; he was afraid that ‎now that he would “descend” to Egypt, he would experience a ‎reduction in intellectual capacity so that G’d would “restrain” ‎Himself when communicating with him, so that he would not be ‎able to serve Him in the manner he was used to. G’d reassured ‎him here that he need not have any such concerns, as the ‎‎Shechinah would remain at his side as long as he would be in ‎Egypt.
‎G’d promises Yaakov that upon his return to the Holy Land, ‎he will have attained great spiritual stature. This is the meaning ‎of the words: ‎גם עלה‎. When the Shechinah which had ‎accompanied him “down” to Egypt, would return to the Holy ‎Land, [which had not contained any Jews during the ‎interval, so that these had not been deprived of its Presence, ‎Ed.], Yaakov would participate in this elevation, ‎עליה‎.

Regarding the verse "lest they multiply, etc., and join also, etc., and go up from the land"—Rashi explained it in two ways. And I have already written elsewhere that the two interpretations are really one: when the holy sparks [nitzotzei kedushah] ascend from these places, automatically all evildoers are scattered and [Israel] comes to redemption. This is the hint in the Masoretic tradition: [Proverbs 11:24] "there is one who scatters yet increases more" [yesh mefazer venosaf od]. But one can explain further: "venosaf od" [and increases more]—beyond the holy sparks ascending from the sitra achra [the Other Side] and being added to holiness, there is something even greater: through the ascent of the holy sparks, an additional light comes from above. This is like what they said [Berachot 34b]: "In the place where penitents [ba'alei teshuvah] stand, even the completely righteous cannot stand." And just as after the Exodus from Egypt there was the receiving of the Torah from Heaven—this is "venosaf od" [and increases more], for "od" [more] means above nature, as I wrote above in parashat Vayigash. This is what is said [Genesis 46:4]: "I will go down with you to Egypt, and I will also surely bring you up [a'elcha gam aloh]"—"gam" [also] refers to additions, as it says "venosaf gam hu" [and join also]. This alludes to "itkasya" [hiddenness] and includes both: the holy sparks that are hidden and submerged within the kelipot [husks/shells], and also the hidden and concealed light above. And through the ascent of the holy sparks, one merits to draw down the hidden and concealed light from above, as I wrote elsewhere.