To whom was this said?
Rashi: It is said to every Yisrael.
Why does it say "Tachas Avosecha Yihyu Vanecha"?
Bava Basra 159a: It is a blessing (that a Tzadik will have children to inherit him - Rashbam). It does not teach that one directly inherits his grandfather [since his father died first].
Mechilta (Yisro, b'Chodesh 2): In the future, every Yisrael will have [600,000] children like [the number] that left Egypt.
Tanchuma (Miketz 3): Everything that happened to Yakov, happened to Yosef - both were born circumcised, were called Bechor, were exiled, and were elevated via a dream. 1
Radak: Kingship comes to Melech ha'Mashi'ach from his ancestors, from David, generation after generation, and it will not cease from his sons.
Malbim: It is a blessing to the children that will be born to them; a king inherits the honor of his fathers. Since his (the king discussed) honor was greater than his fathers' - e.g. his father was a master, and he is a great king - his sons inherit only his fathers' level - "Tesiseimo l'Sarim b'Chol ha'Aretz."
Malbim (Derech ha'Muskal): Refer to 45:17:3:3.
Rashi (Bereishis 37:2) adds that both were hated, and both of their brothers wanted to kill them.
Why does it say "Tesiseimo l'Sarim b'Chol ha'Aretz"?
Malbim: Refer to 45:17:2:5.
Malbim (Derech ha'Muskal): Your sons and Talmidim - the latter are 'sons' of intellect - will learn Chachmah that you received from your fathers and teachers. You will make them officers in all the land - they will rule over the land and physicality, and subdue it under intellect.
