What did Yaakov mean when he said that "Yosef's 'bow' was firmly emplaced, and that his arms were gilded"?
Rashi and Seforno: He meant that Yosef became strong, 1 when Pharaoh accepted him and placed the golden ring on his finger.
Rashi (to 49:26, citing Sotah 36b): He was referring to Yosef's strength 2 of character, which he displayed by overcoming his Yetzer- ha'Ra, when confronted by the wife of Potifera.
Targum Onkelos: Yosef's prophetic dreams materialized because he kept the Torah in secret; and because he trusted implicitly in Hashem, gold was placed on his arm and he inherited kingship.
Rashi (citing Sotah 36b): He overcame his desire for Potifar's wife. 3 The semen came out of his fingertips. 4
Rashbam: Yaakov is describing Yosef's strength by comparing him to an archer, who bends his arms 5 to draw the string of an extremely tough bow, which shoots an arrow to a great distance, but whose string only a strong man is capable of drawing.
Malbim: He did not shoot arrows back at the ones who shot at him. His arms were filled with Paz (gold); i.e. he gave to them wealth and gifts!
Ha'amek Davar: "Kashto" is like "Keshes Nechushah Zero'sai" (Shmuel II 22:35) - the harder the bow, the further it shoots arrows. Yosef's bow became strong, to shoot evil recompense to his brothers, but he showed the beauty of his hands, and bestowed them with Paz (gold; wealth and gifts).
Which he refers to as a bow, because seed shoots like an arrow.
Riva: He stuck his fingers in the ground to pain himself and overcome his Yetzer. Targum Yonasan: His Ever Tashmish, which had become hard with desire, went limp, when he decided to refrain. He overcame his Yetzer-ha'Ra from the powerful teachings of his father. Consequently, he became a sustainer and his name was engraved on the stones of the Efod.
Rashi also gives this explanation at the end of his comments to 49:26. Refer also to 39:11:3:1 (See Perush Yonasan).
"Va'Yafozu" means to bend, as in Shmuel II 6:16.
What did Yaakov mean when he added, "this was from the Mighty One of Yaakov, from there he shepherded the stone of Yisrael"?
Rashi #1: This came to Yosef from Hashem, the Mighty One of Yaakov, 1 and from then Yosef arose and ruled over 2 the mainstay of Yisrael (i.e. father and sons). 3
Targum Yonasan: He overcame his desire due to the sharp teachings of his father. And because of that deed, he merited to become the sustainer (of the whole of Egypt), and to be engraved together with the names of his brothers [on the stones of the Efod].
Seforno: This salvation came about through the G-d of Yaakov, the G-d who safeguards Yisrael - like one safeguards a precious stone.
Rashbam: The victory and kingship that Yosef ultimately attained was granted to him by Ha'Kadosh-Baruch-Hu (the shepherd or sustainer of Yaakov), 4 and by which he was able to sustain his father and family 5 in Egypt.
Ramban: This is similar to the Berachah that Yaakov conferred upon Efrayim and Menasheh. 6
Rashi #2 (to 49:26): He overcame his desire through seeing the image of his father. Refer to 39:11:3:1 and 39:11:3.2:1.
Ohr ha'Chayim: Hashem gave to him Abirus (strength) to overcome the great forces of evil tempting him to sin - "Hashem Lo Ya'azvenu b'Yado" (Tehilim 37:33). Via this, Yosef merited to become the cornerstone - "Even Ma'asu ha'Bonim [Hayesah l'Rosh Pinah]" (Tehilim 118:22).
Malbim: This was in the merit of Yaakov, and Elokim, who dwells over Yaakov. Hashem prepared him to shepherd (sustain) Even Yisrael - "l'Michyah Shelachani Elokim Lifneichem" (45:5).
Ha'amek Davar #1: It was via the great strength of Yaakov, who was strong in the Midah of Shalom (refer to 31:46:152:1 and the note there; refer to 32:26:151:2). Yisrael was compared to a rope composed of many strands, "Yaakov Chevel Nachalaso" (Devarim 32:9). Above it is thick, and below each strand is separate by itself. So Hashem is the Neshamah of the Neshamos of Yisrael; when a Yisrael is in pain, the Shechinah feels pain (Sanhedrin 46a). If one isolated string is moved below, the thick rope above feels it. This is why a Yisrael may not take vengeance against another. This is why Yosef did not take vengeance.
Ha'amek Davar #2: "Ro'eh" is like "u'Re'e Emunah" (Tehilim 37:3) or the word "Ra'yon" in Koheles; he invests much thought. Yisrael in exile are compared to earth - "v'Hayah Zar'acha ka'Afar ha'Aretz" (28:14). The nations are compared to water - "Mayim Rabim Lo Yuchelu le'Chabos Es ha'Ahavah" (Shir ha'Shirim 8:7), When water inundates earth, it totally dissolves it. From Yosef's wondrous Midah of Chesed towards one who did evil to him, Yisrael's earth can become a hard rock. Even a raging sea only rolls it, but it does not break it. If Yisrael in Galus have scattered intents and pursue each other, they perish one by one. If they are tied and become Even Yisrael, no creation can overcome them. However, "mi'Sham" implies that Hashem caused that they not be flooded. Rather, they are unified, and not washed away.
Ha'amek Davar: We find that this refers to Hashem - "Nadar la'Avir Yaakov" (Tehilim 132:2).
Via whose word he sustained... ' (Targum Onkelos).
Rashi (explaining Targum): "Even" is the acronym of 'Av u'Ven.'
Rashbam: As in the Pasuk earlier, Bereishis 48:15.
The 'Nun' in "Even" is superfluous (See Rashbam).
What is a deeper meaning of the term "Even Yisrael"?
Maharal (Ner Mitzvah, p. 19): Yaakov's trait was to be holy, detached from and above the physical. He is comparable to stone, which can overpower other materials, and cannot be affected by them (unlike most Chomer, which by definition can be molded and changed). 1
Maharal (Nesivos Olam, Nesiv ha'Torah Ch. 13, p. 54) explains the contrast between stone and [other material] Chomer. (For a brief example of the Maharal's terminology of Chomer and Tzurah, refer to 22:5:151:2*.)
QUESTIONS ON RASHI
Rashi writes: "... But Chazal interpreted [this verse] regarding his overcoming his Yetzer for his master's wife...." Why was this accomplishment the specific cause of Yosef's blessings?
Maharal (Chidushei Agados Vol. 2, p. 73, to Sotah 36b): One who transcends his material (Chomer) aspect shows that he rules over it; so too, by overpowering his Yetzer, Yosef merited to become a ruler. 1
Also refer to 39:1:1.6:1 and the note there.
Rashi writes: "... The seed emerged from between his fingers." Why did this occur?
Maharal (Chidushei Agados Vol. 2, p. 73, to Sotah 36b): Yosef was to Yaakov like the primary branch emerging from a tree 1 - strongly attached, yet not as powerful as the trunk itself. Unlike Yaakov who had never seen Keri (Rashi to 49:3), Yosef's seed departed him. 2
Refer to 37:2:1.09:1.
Maharal: The potential that Yosef did not fulfill was corrected by his brother, Binyamin. Also refer to 43:30:1.1:1.
Rashi writes: "'Even Yisrael' - [Targum interprets this] as a contraction of 'Av u'Ven,' to mean, '[Yosef provided sustenance] for the father and children of Yisrael.'" Why was this the specific cause of Yosef's blessings?
Maharal (Nesivos Olam, Nesiv ha'Torah Ch. 8, p. 36): The Gemara (Sanhedrin 92a) associates Yosef with the Pasuk, "u'Veracha l'Rosh Mashbir (a blessing upon the head of the provider)" (Mishlei 11:26). Yosef brought down Heavenly abundance upon his family; he too was blessed with "blessings of the Heavens above" (49:25).