1)
Why does the Torah see fit to tell us about children of Nachor's concubines?
1.
Rashi: Refer to 22:20:4:1.
2.
Ramban #1: The Torah is simply completing the news that was told to Avraham.
3.
Ramban #2: It is presenting the Yichus of Nachor, to teach us that his entire family was fit for Avraham's children to marry into (not just Rivka).
2)
Rashi (to 25:20) writes: Rivka was born at this juncture, at the time of the Akeidah. But all the sons of Nachor are listed here; and they could not have all been born just now?
1.
Gur Aryeh (to 25:20): The term "Avraham was informed" (va'Yugad) (22:20) implies news that had just happened; that news must have been of Rivka's birth.
