What is the corollary between the first two phrases of this Pasuk?
Rashi: The greatness which Yosef attained in the previous Pasuk 1 was granted to him by the G-d of his father, who will (therefore) help him, and his heart was with Hashem when he did not listen to his mistress, and He will (therefore) bless him.
Ramban (citing the Ibn Ezra): The 'Mem' of "me'Kel" extends to "v'Es Shakai", so that what Ya'akov meant was that that greatness was also granted to him by Shakai, who would bless him.
Seforno: The greatness which Yosef attained in the previous Pasuk 2 was granted to him by the G-d of his father, who assured him that his children would rise again after they had fallen, 3 and he would not fall again. Moreover, Keil Shakai had promised him 4 that he (Yosef) would have precedence over his brothers in that two tribes were destined to emerge from him. 5
Targum Yonasan: "The G-d of your father will assist you and the One who is called Shakai will bless you". 6
The Seforno adds that "vi'Yevarecheka" refers to the direct Berachah that Yosef would receive from Hashem (as opposed to the Berachah that he gave Efrayim and Menasheh, which was via the redeeming angel, as Ya'akov specifically stated earlier [See 48:16], and as opposed to the Berachos that Yitzchak blessed him and the Berachos that Moshe blessed the generation that entered Kena'an. Indeed, this was a promise that his father Yitzchak gave him. See Toldos, Bereishis 28:3), to which Moshe referred before the sin of the spies (See Devarim, 1:11).
In the way described by the continuation of the Pasuk.
What was Ya'akov referring to when he blessed Yosef with "the Berachos of the heaven above and of the deep that crouches below?
Seforno: The former is a blessing for longevity, the latter, for sustenance and wealth.
Targum Yonasan: The former referred to the blessing of dew, the latter was a blessing that the underground fountains should rise and cover the growing plants. 1
The Rashbam too, explains this Berachah in the same way.
What was he referring to when he blessed him with "Birchos Shadayim va'Racham"?
Rashi: He was blessing the seed of the fathers 1 (that it should impregnate) and the mothers' wombs (that the babies should not be stillborn).
Targum Yonasan: He was referring to the breasts from which Yosef suckled and the womb in which he grew. 2
Hadar Zekenim, Moshav Zekenim: The mothers should have enough milk to nurse the babies; Da'as Zekenim - also, they should not miscarry. Moshav Zekenim - the womb should not be uprooted. 3
The seed shoots like an arrow, and Onkelos translates "Yaroh Yiyareh" (Yisro, Shemos 19:13) as Ishteda'ah Yishtetdi" (from the root Shadi). Moshav Zekenim rejects this. Why should the Torah use Arame'ic? And why is Shadayim in the plural? And why is the Brachah attributed to shooting?
Even when blessing Yosef, Ya'akov referred to Rachel, a sign of the love that he bore her (Peirush Yonasan).
רש"י: שָׁדַיִם...שהזרע יורה כחץ: למה רש"י נדחק כך באונקלוס?
גור אריה: יש לפרש [לא כרש"י] שהשדים מיוחדים להניק ולתת, והרחם לקבל, ולכן האב נקרא 'שדים' והאם 'רחם'.
היכן נתברך יעקב בברכת תהום (ככתוב בהמשך- "ברכות אביך"), ומה משמעותה?
מהר"ל (גבורות ה' פ"כ עמ' צא ד"ה וישק): מי הבאר היו עולים לקראת יעקב בגלל ברכה זו, וברכה זו מורה על נצחיות בני יעקב כי הם דבקים במקור הברכה.
למה חזר משה ובירך את יוסף בברכות שכבר ברכו יעקב?
גור אריה (דברים לג,יג): יעקב ברך את יוסף עצמו ואפשר שזה היה מתקיים רק בחלק מהשבט, אבל משה ברך את כל השבט.