הַמַּלְאָךְ הַגּוֹאֵל וְגוֹ׳. פֵּרוּשׁ, מַאֲמַר ה׳ אֲשֶׁר יְצַו ה׳ אֶת יְדִידָיו אֵלָיו יִקָּרֵא שֵׁם מַלְאָךְ, כִּי קוֹל ה׳ חוֹצֵב לַהֲבוֹת אֵשׁ (תהלים כט:ז). וְהוּא כַּוָּנָתוֹ בְּאָמְרוֹ ״הַמַּלְאָךְ״ וְגוֹ׳, פֵּרוּשׁ שֶׁיִּהְיֶה מֵימְרָא דַּה׳ בְּסַעֲדָם וִיבָרֵךְ אוֹתָם. המלאך הגואל אותי, "The angel who redeems me, etc." Jacob referred to any word of G'd which He issues to or on behalf of those those who love Him as מלאך. This is analogous to Psalms 29,7: "The voice of G'd kindles flames of fire." Jacob expressed the hope that G'd's word would always come to the assistance of Joseph's sons and bless them.
וְיִקָּרֵא בָהֶם שְׁמִי וְגוֹ׳. פֵּרוּשׁ, שֶׁיִּהְיוּ בְּהַדְרָגַת שְׁלֹשָׁה אָבוֹת, וּכְשֵׁם שֶׁאֵין אָדָם בָּעוֹלָם יָכוֹל לְנַתֵּק אוֹ לְקַלְקֵל בְּאֶחָד מִשְּׁלֹשָׁה אָבוֹת, וְאֵין צָרִיךְ לוֹמַר בְּכוּלָּן יַחַד, כְּמוֹ כֵן הֵם. ויקרא בהם שמי, "and may my name be called upon them, etc." Jacob wished that Joseph's sons should reflect the spiritual level of the patriarchs. While it is quite impossible for any Jew to completely sever the connection with all three of the patriarchs, Jacob blessed Ephrayim and Menashe in that they would never fail to reflect the spiritual values of even one of the patriarchs.
עוֹד יִרְצֶה לְשׁוֹן יְקָר וּגְדֻלָּה, פֵּרוּשׁ שֶׁיַּגִּיעַ בְּאֶמְצָעוּתָם יְקָר לְשֵׁם אָבוֹת, וְהוּא עַל דֶּרֶךְ אָמְרוֹ (משלי כ״ג:כ״ד) ״גִּיל יָגִיל אֲבִי צַדִּיק״, וְכֵן הוּא אוֹמֵר (משלי י״ז:ו׳) ״עֲטֶרֶת זְקֵנִים בְּנֵי בָנִים״, וְזֶה יִהְיֶה בְּאֶמְצָעוּת הֲכָנָתָם הַהֲגוּנָה וְדַרְכָּם הַיָּשָׁר עַד שֶׁיַּגִּיעַ יְקָר לַאֲבוֹת אֲבוֹתָם: Jacob may also have expressed the hope that the reputations of the patriarchs would be enhanced by the conduct of Joseph's sons in the future. We find such an idea in Proverbs 23,24: "the father of the righteous will rejoice greatly;" we also have a similar statement in Proverbs 17,6: "Grandchildren are the crown of their elders." All of this is predicated on the grandchildren following in the footsteps of their illustrious forebears.
עוֹד יִרְמוֹז כִּי יִהְיֶה לָהֶם חִבּוּב הַזְכָּרַת שְׁמָם לִפְנֵי ה׳ כְּחִבּוּב הַזְכָּרַת שֵׁם אַבְרָהָם יִצְחָק וְיַעֲקֹב. וּכְמוֹ כֵן תִּמְצָא שֶׁאָמַר הַנָּבִיא (ירמיהו ל״א:כ׳) ״הֲבֵן יַקִּיר לִי אֶפְרַיִם וְגוֹ׳ כִּי מִדֵּי דַבְּרִי בּוֹ״ וְגוֹ׳, הֲרֵי כִּי שְׁמוֹ שֶׁל אֶפְרַיִם נִתְיַקֵּר בְּעֵינֵי ה׳ וּמַזְכִּירוֹ בְּחֵשֶׁק וְחִבָּה יְתֵרָה: Jacob also hinted that mentioning the names of Ephrayim and Menashe would have as positive an effect in the ears of G'd as has mentioning the names of the patriarchs themselves. This sentiment is expressed in Jeremiah 31,19 when the prophet exclaims that every time G'd merely hears the name of Ephrayim mentioned He recalls him with feelings of mercy and has pity on his plight.
וְיִדְגּוּ לָרֹב וְגוֹ׳. הַכַּוָּנָה עַל דֶּרֶךְ מַה שֶׁפֵּרַשְׁתִּי בְּפָרָשַׁת בְּרֵאשִׁית בְּפָסוּק (בראשית א:כב) ״וַיְבָרֶךְ אוֹתָם״ וְגוֹ׳ הָאָמוּר בַּדָּגִים, כִּי הֻצְרַךְ ה׳ לְבָרְכָם לְצַד שֶׁמְּקוֹם דִּירָתָם הוּא נֶגְדִּיִּי בַּקָּצֶה הָאַחֲרוֹן לִבְחִינַת הַלֵּידָה, לָזֶה הִגְדִּיל בָּהֶם כֹּחַ הַמּוֹלִיד לְהוֹלִיד אֲפִלּוּ בַּמַּיִם, וְכָאן אָמַר יַעֲקֹב שֶׁיִּדְגּוּ כַּדָּגִים בְּרִבּוּי הַלֵּדָה וְיִהְיֶה לָהֶם גֶּדֶר זֶה בָּאָרֶץ, וּכְפִי זֶה תִּהְיֶה בִּרְכָתָם גְּדוֹלָה מִבִּרְכַּת הַדָּגִים לֶהֱיוֹתָם בַּמַּיִם, וְהָבֵן. וידגו לרוב בקרב הארץ, "and they will multiply on earth just like fish." Jacob's considerations may have been similar to the blessings G'd bestowed on the fish in Genesis 1,22.1 explained there that a special blessing for the fish was called for due to their habitat being less suited for successful and enduring procreation than the conditions prevailing on dry land. G'd therefore increased the fish's natural reproductive powers to counter the negative conditions prevailing in their habitat. Jacob too accorded Joseph's sons greater powers of reproduction when he blessed them by comparing their fruitfulness to that of fish. Inasmuch as Ephrayim and Menashe did not reside in regions which are hostile to human reproduction, Jacob's blessing was even stronger than G'd's blessing for the fish.
וְדִקְדֵּק לוֹמַר בְּקֶרֶב, רֶמֶז שֶׁיִּהְיוּ נֶחְבָּאִים בִּפְנִים, עַל דֶּרֶךְ מַה שֶׁאָמַר לָהֶם יְהוֹשֻׁעַ (סוטה לו:) בִּזְמַן שֶׁנִּתְקַיְּמָה בִּרְכַּת יַעֲקֹב בָּהֶם: ״לְכוּ הַחְבִּיאוּ עַצְמְכֶם בַּיְּעָרִים״, כִּי יְהוֹשֻׁעַ פֵּרֵשׁ הַכָּתוּב כְּפֵרוּשֵׁנוּ. וְיֵשׁ דְּרָשָׁה בָּזֶה (ברכות נה:) שֶׁהִמְשִׁילָם לְדָגִים שֶׁאֵין עַיִן הָרַע שׁוֹלֶטֶת בָּהֶם, וּכְפִי זֶה אָמְרוֹ בְּקֶרֶב הָאָרֶץ פֵּרוּשׁ, הֲגַם שֶׁיִּהְיוּ בְּקֶרֶב הָאָרֶץ, וּבָזֶה הֵם בְּגָדֵר עֶלְיוֹן מֵהַדָּגִים. Jacob deliberately chose to say בקרב, "in the midst of the earth," instead of merely saying "on earth." This was a hint that at some time in the future Joseph's descendants would "hide" within the earth as we know from Sotah 36 where Joshua is reported as having advised the members of that tribe to hide in the forests (to prevent attracting envy and jealousy due to their being numerous). This need arose only because Jacob's blessing had been fulfilled and they had multiplied at a faster rate than the other tribes. Berachot 55 sees in Jacob's phraseology a hint that the descendants of Joseph would be immune to the evil eye just as the fish are immune to the evil eye. The fish enjoy that status only thanks to their remaining under the surface of the water and therefore not visible. Jacob blessed the sons of Joseph that they would enjoy this immunity even while visible on earth, i.e. בקרב הארץ.