What is "Ben Poras Alei Ayin"?
Targum Onkelos: Yosef is a fruitful son, who can be compared to a vine (Da'as Zekenim, Hadar Zekenim - tree) that one plants beside a spring.
Rashi: When Ya'akov met up with Eisav, whereas all other mothers bowed down to Eisav ahead of their sons, the Torah records that Yosef and Rachel bowed down to him. This was because Yosef went in front of his mother to prevent Eisav from setting his eyes on. That is why his father blessed him here that - because he made himself tall to protect his mother from the eyes of Eisav, he merited greatness. 1
Ramban and Seforno: Yosef is a son who is like a tree with many branches, which is planted next to a spring, whose water supply will never cease. 2
Targum Yonasan: Ya'akov compares him to a vine that grows beside springs of water that bores through the rock-peaks. 3 And just as it is superior to all the non fruit-bearing trees, so too, did Yosef in his wisdom and with his good deeds, surpass all the sorcerers of Egypt.
Rosh (41:14): Everything that happened to Yakov happened to Yosef. Yakov was called Bni Bechori Yisrael, and Bechorah was given to Yosef. Yakov was exiled to Charan, and Yosef was exiled to Mitzrayim. Both were elevated through dreams. Refer to 37:2:1:2.
Alternatively, he merited to be above the eye (he is not subject to the Ayin ha'Ra [Rashi]). Refer to 48:16:1:1.
The Ramban adds that the words "Poras" and "Banos" hint at the two tribes that emerged from Yosef., which Ya'akov declined to mention specifically, since he included Levi in the Berachos, and whenever Levi is mentioned, Yosef is listed as one tribe.
With reference to the Nisyonos with Potifar's wife and his brothers Peirush Yonasan).
What are "Banos Tza'adah Alei Shor"?
Rashi #1: Ya'akov was referring to the occasion following Yosef's appointment as viceroy of Egypt, when he rode in state around Egypt, and all the aristocrats' daughters climbed the walls to gaze at 'the handsome prince'. 1
Rashi #2 (citing Targum Onkelos): It refers to the two tribes that would emerge from him (Efrayim and Menasheh), who would receive two portions of inheritance. 2
Rashbam: He was referring to the Egyptian women, such as the wife of Potifera and her friends, who made a point of going to look at him. 3
Seforno: It refers to the branches that climb the wall, 4 whose sudden appearance of the tree and its branches known to the people on the other side. So too, was Ya'akov unaware of the existence of Yosef and Yosef's sons, until in a flash, they suddenly appeared to him. 5
Da'as Zekenim, Hadar Zekenim: [Every part of] his land produces grain and Peros, up to the wall of the city.
Moshav Zekenim: Why is Tza'adah singular? Each stepped in front of the other [to get a better view]. Targum Yonason - in an effort to get him to look at them, they threw various golden ornaments in front of him, but he refused to look up, to avoid punishment on the Final Day of judgment.
He referred to them as daughters because of the daughters of Tzelafchad (who came from Menasheh), who took portions on both sides of the Yarden.
As Ya'akov explicitly told Yosef (See 48:11). See also Ba'al ha'Turim.
Why did Ya'akov repeat the term "Ben Poras"?
Rashbam: As is the often the case in the Torah, Ya'akov introduces a point briefly and repeats it in more detail. 3 What Ya'akov is therefore saying is that Yosef is a flourishing son, a son who flourishes over the eye - he is taller than the eye in stature and in good looks.
Targum Yonasan: Yosef is a son who grows (spiritually) fruitful, a son who grows to the point that he overcomes his Yeitzer-ha'Ra as can be seen in the incident concerning the wife of Potifera and in the incident concerning his brothers. 4
See Ramban's objection to this explanation.
As we find with Potifar, Pharaoh, and ultimately, with the whole of Egypt. (EC)
The Rashbam gives numerous examples of this throughout Tanach - see for example Parshas Beshalach, Shemos 15:6).
Presumably, this refers to returning to them good in place of evil, being careful not to shame them in front of others... (PF)
Why is Yosef the only son whose Brachah does not begin with his name?
Moshav Zekenim: It is the way of kings and great people that we do not begin with their name.
רש"י: על שם...בנות צלופחד: גור אריה: לכאורה פרוש רש"י דחוק?
גור אריה: לאונקלוס יש לפרש (לא כרש"י) שדימה את יוסף לגפן ואמר ש"בנות" הגפן- הבדים שיוצאים ממנו, יתארכו ויגיעו עד ה"שור"- חומת הכרם. ורומז הפסוק על שני שבטיו שהם הבדים שלו שיתארכו כגפן עצמו ויקבלו נחלה כמו השבטים.
רש"י: שלא תשלוט בזרעו עין רעה: למה זכה לברכה זו?
מהר"ל (חידושי אגדות ח"ג עמ' קכו ד"ה ויש, ב"ב דף קכג.): יוסף היה עליון ונסתר (כיעקב ורחל) ולכן העין לא שולטת בו.
מהר"ל (חידושי אגדות ח"ד עמ' עב, ד"ה עין, זבחים דף קיח:): יוסף זכה לכך כי לא רצה לראות בעיניו את מה שאינו שלו [-אשת פוטיפר] ולכן הייתה לו מדרגה נבדלת [מהחומר, והוא רוחני].
מהר"ל (חידושי אגדות ח"ג עמ' לה, ד"ה אנא, ב"מ דף פד.): יוסף שהוא עיקר תולדות יעקב, ירש מאביו כח נסתר פנימי, כי ליעקב הייתה את מעלת האמצע- בין אברהם ליצחק. 1
אברהם מידתו חסד- ימין, ויצחק מידתו דין- שמאל, ויעקב מידתו רחמים הממצעת בין שניהם.
רש"י: שלא תשלוט בזרעו עין רעה: במה זכה בעטיה של ברכה זו?
מהר"ל (נתיבות עולם, נתיב העושר פ"ב עמ' רכז, ד"ה ועוד): יוסף היה בעל ברכה ואסף כל כסף וזהב שבעולם כי העין לא שולטת בו.
מהי ברכת "בן פורת"?
מהר"ל (נתיבות עולם, נתיב גמ"ח פ"א, עמ' קמז ד"ה ובפ"ק): יוסף היה מפואר וחשוב ולכן נעשה לו כילה, וכן זוכה העוסק בתורה וגמ"ח לחשיבות של נוי.