1)
Why is Bilhah called "Shifchas Rachel" (and similarly regarding Zilpah in the next verse)?
1.
Ha'amek Davar: She acted towards Rachel like her Shifchah, and so Zilpah acted towards Leah.
Why is Bilhah called "Shifchas Rachel" (and similarly regarding Zilpah in the next verse)?
Ha'amek Davar: She acted towards Rachel like her Shifchah, and so Zilpah acted towards Leah.