Why did Hashem refer to Yisrael as His "firstborn son"? In what sense are Bnei Yisrael a "Bechor," and what is the significance of this status?
Rashi #1: :In the simple sense, "Bechor" means (not 'firstborn,' but) an expression of greatness (i.e. importantance). 1
Rashi #2: In the Midrashic sense, here Hashem endorses Yaakov's purchase of the birthright from Esav, by calling Bnei Yisrael the Bechor. 2
Seforno: Because they have a place of honor with Hashem, since they were the first to worship Him. 3
Gur Aryeh: "Bechor" means 'first and foremost.' Yaakov was conceived before Esav (Rashi to Bereishis 25:26); and Bnei Yisrael were the first nation whom Hashem knew (i.e. entered a relationship with). 4
Maharal #1 (Gevuros Hashem Ch. 29, p. 113): Am Yisrael is the beginning of Hashem's revealing His power in the world, just as a firstborn is the first revelation of his parents' ability. Yisrael is sanctified, just as a Bechor is holy, due to his distinction as firstborn. 5
Maharal #2 (Netzach Yisrael beg. Ch. 11, p. 65): A child is created from the very self of the parent; Klal Yisrael are called 'sons of Hashem' in the sense that we receive beneficence from Hashem Himself. 6 But the term 'son' alone does not preclude the possibility of additional children! Therefore, we are also called the "firstborn" - of which, by definition, there can be only one! Just as Hashem is One, Yisrael who reveals the existence of Hashem, must also be one. 7
Does this explanation fit with the following Pasuk? See 4:23:0.1:1.
Gur Aryeh: If so, the word "Beni Bechori" in this context simply means, 'the one I endorse as firstborn of his father (Yitzchak).'
Seforno: Even though He expects all nations to call His Name (See Tzefanyah 3:9). In a similar vein, the Meshech Chochmah explains that, just as a Bechor gives his father the status of a father, so too, were Yisrael the first to acknowledge Hashem and to give Him the status of Master of the world.
Gur Aryeh: Thus, the term "Beni Bechori" relates to Hashem. It was because Yaakov knew this, that he saw the necessity of purchasing the birthright from Esav. Maharal (Gevuros Hashem Ch. 29, p. 114) - Hashem already planned to create Yisrael, even before Creation of the world. They are Creation's purpose and goal. Also refer to Bereishis 25:26:1.2.
'Holiness' means being set apart. A firstborn is not merely the first among equals. He was the one who actualized his father's status as a father, while subsequent children merely continued and added to it. (EK)
Other nations are incidental; meaning they were created not for their own sake, but to serve Yisrael. On the other hand, Klal Yisrael fulfill Hashem's ultimate will, to reveal Himself to his creations. Thus they reveal Hashem's essential truth - i.e., His will in creation (EK). Compare Maharal (Tif'eres Yisrael Ch. 17, p. 56).
Hence, it is impossible that any other nation will ever be called 'children' to Hashem.
QUESTIONS ON RASHI
Rashi writes: "... Here, Hashem endorsed Yaakov's purchase of the birthright from Esav." If Yisrael deserves to be the Bechor (see 4:22:1), why was Esav born before Yaakov in the first place? What did purchasing the birthright accomplish?
Maharal (Gevuros Hashem Ch. 29, p. 113): The closer something is to its ultimate Cause (Hashem), the further it is from being expressed in the physical world. (That it was why Yaakov was second to emerge.) Nevertheless, in truth the birthright as firstborn was meant for Yaakov; and once he grew up, he attained that status. 1
Maharal (ibid.): The same is true for Klal Yisrael as a whole. They were last to emerge as a nation, yet the most fitting to be the Bechor (first and foremost) in the world. Also see Bereishis 25:26:1.1 and Bereishis 25:26:1.2.
