וַיִּתֵּ֤ן לָבָן֙ לָ֔הּ אֶת־זִלְפָּ֖ה שִׁפְחָת֑וֹ לְלֵאָ֥ה בִתּ֖וֹ שִׁפְחָֽה׃
At ibinigay ni Laban si Zilpa na kanyang aliping babae kay Lea na kanyang anak na babae, upang maging kanyang alipin.
Chizkuni
את זלפה שפחתו, “his servantmaid Zilpah;” how could the Torah describe them as servantmaids when they were actually Lavan’s daughters? (Compare Bereshit rabbah 74,13) We must therefore assume that the Torah used the terminology of the people at that time who described their daughters born by concubines as their servantmaids.
Da'at Zekenim
את זלפה שפחתו, “his servant-maid Zilpah.” Why is Lavan’s daughter called his “servant maid” here? It was customary in those days to refer to the offspring of one’s concubines as “servants,” to distinguish their status from the offspring of one’s wives. (Pirke de Rabbi Eliezer, chapter 36)
Or HaChaim
ללאה בתו שפחה. for his daughter Leah as a maidservant. Why did the Torah have to mention that Leah was Laban's daughter? Surely we know this by now! If it was sufficient to write: "Laban gave her her his maidservant Zilpah," why did the Torah have to add "to Leah his daughter" at the end of the same verse? Besides, why did the Torah write שפחה, maidservant, instead of לשפחה, as a maidservant?