Rashi on Genesis 31:50/רש"י על בראשית ל״א:נ׳

1בנתי....בנתי The word is written twice, referring once to Leah and Rachel and the second time to the handmaids, because Bilhah and Zilpah were also his daughters from a concubine (Genesis Rabbah 74:13).

2אם תענה את בנתי IF THOU SHALT AFFLICT MY DAUGHTERS by refusing them thy companionship (Yoma 77b).