What did Rachel mean when she said "v'Seiled Al Birkai"?
Rashi, Targum Onkelos and Targum Yonasan: It means 'I will bring up the children that Bilhah bears.' 1
Bechor Shor: And they will be attributed to me.
Why did Rachel say "v'Ibaneh Gam Anochi Mimenah"?
Rashi: When Rachel pointed out that Avraham made efforts to have children from Sarah even though he already had a child from Hagar, Yakov replied that Sarah first gave her maidservant to Avraham; to which Rachel responded by giving Bilhah to Yakov 1 (so that, like Sarah, she would subsequently have a child).
Tosfos ha'Shalem (2:6, and 6, citing R. Yakov of Vienna): The letter Hei is needed for children. Bilhah has one for herself, and one for me.
Seforno: She meant that the jealousy that she would inevitably feel of Bilhah would enable nature to take its course and that she too (like her sister), would subsequently give birth.
After setting her free (Targum Yonasan). Tosfos ha'Shalem (4:3) derives "l'Ishah" - not for a concubine.
What did Rachel mean "v'Ibaneh Gam Anochi Mimenah"?
Seforno: She meant that the jealousy that she would inevitably feel towards Bilhah would enable nature to take its course and that she too, would subsequently give birth.
Sarah said "Ba El Shifchasi Ulai Ibaneh Mimenah." Why did Rachel call Bilhah 'Amasi', did not say 'perhaps', and added v'Seiled Al Birkai?
Tosfos ha'Shalem (3): Amasi is like Umasi (from my nation. Bilhah and Zilpah were Lavan's daughters from Shifchos - Pirkei d'R. Eliezer 36). Sarah was unsure if she will give birth 1 . Sarah could not say 'I will put the children on my knees', for she was old. 2
Why did Sarah mention Bi'ah before 'my Shifchah', and Rachel reversed the order?
Ohr ha'Chayim: Hagar remained a Shifchah after the Bi'ah. Rachel freed Bilhah (Targum Yonason) before the Bi'ah, and Yakov married her like a wife.
QUESTIONS ON RASHI
Rashi writes that entering a Tzarah into the house is a merit to have children. Why is this?
Ohr Yechezkel Midos p.231: "V'El Zeh Abit El Oni u'Nechei Ru'ach"