Why did Yitzchak begin the Berachah with a 'Vav' ("Veyiten")?
Rashi #1: He blessed Ya'akov that Hashem should give him, again and again.
Rashi #2: It is a continuation to the previous Pasuk - 'Besides the beautiful aroma that Hashem already blessed you, may He also give you from the dew of the Heaven ... '.
Why did Yitzchak bless Yakov "Elokim will give to you", and in the similar Brachah to Esav, he did not mention Elokim?
Rashi: "Elokim" denotes Midas ha'Din - implying that Ya'akov 1 will only merit the Berachos if he deserves them. Whereas to Esav he said "Mish'mnei Shamayim Yih'yeh Moshavecha" - whether he deserves it or not. 2
Teshuvos Beis ha'Levi Drush 3 DH uv'Zeh, from the Zohar: Only Yakov receives directly from Hashem.
Even though he thought that he was blessing Esav, he was not aware of the fact that Esav was not worthy of the Berachos, and that his words therefore, were directed at the one who was worthy.
Shlomo ha'Melech in Melachim 1, chapter 8), took his cue from Yitzchak, and applied the same distinction to a Jew and a Nochri who would Daven in the Beis-ha'Mikdash (See Rashi). The reason for this is because, as opposed to a Jew, who understands that if his prayer is not accepted, it is because he is not worthy, a Nochri thinks that since he took the trouble to pray to Hashem, Hashem is obligated to respond favorably. So if He doesn't, he turns his back on Him.
What is the gist of the Berachah that Yitzchak was giving Ya'akov? What is the significance of the "dew of the Heaven and the fat of the earth"?
Rashi and Targum Unk'lus: He blessed him literally with the dew of the Heaven ... .
Targum Yonasan: He blessed him with 'the best of the dews from the Heaven, from the best of the underground springs and bountiful plants of the earth ... '.
Ramban #1: That Hashem should give him from the dew of the Heaven and the fat of the earth - more than the norm. 1
Ramban #2: That He should give him from the dew of the Heaven and the fat of the earth an abundance of grain and wine. 2
Ramban #3: Bearing in mind that what Hashem gives is forever, he blessed him that Hashem should give him from the dew of the Heaven forever, and that his land should be the most fruitful in the world. 3
Ramban (citing the Ibn Ezra): That He should give him from the dew of the Heaven and from the fat of the earth. 4
Since 'from the dew of the Heaven and the fat of the earth' is not a Berachah per se, as that is a natural occurrence that happens everywhere.
As if there was no 'Vav' at the beginning of the word "v'Rov".
Because the 'Mem' from "mi'Tal" extends to "Mish'manei ... " (so that it reads "mi'Mishmanei ha'Aretz").
And why did he add "ve'Rov Dagan ve'Sirosh"?
Ramban: Refer to 27:28:3:4.
Seforno: He blessed him that he should have sufficient to feed others. 1
רש"י: יתן ויחזור ויתן: מה המשמעות שיחזור ויתן?
רא"ם: גם אם היה כתוב 'יתן לך' היה משמע שיתן לו את אותה הברכה שוב ושוב [כי לא נאמרה הגבלה על הברכה], אלא הכוונה שיתן לו את הברכות שלו ויחזור ויתן לו את ברכות אביו.
גור אריה: כוונת הפסוק שיעקב נתברך בברכה בלי מצרים [-בלי גבול], וכל מה שיתן לו- יחזור ויתן לו עוד.
רש"י: יתן ויחזור ויתן : מנין לדרוש כך את הפסוק?
גור אריה: הוי"ו של "ויתן" מיותרת כי אין לה חיבור למה שכתוב לעיל.
רש"י: ומדרש אגדה יש להרבה פנים: למה ציין רש"י למדרשים שישנם?
גור אריה: יש לתמוה מדוע ברך יצחק את יעקב רק בברכות גשמיות? ולכן ציין רש"י למדרשים שיש כאן גם ברכות רוחניות.