Why does it say "va'Tishtachavenah" (they bowed, in the feminine)?
Da'as Zekenim, Rosh: The maidservants bowed, but their children did not. They reasoned, our mothers are not as important as we are. 1 Bnei Leah bowed when they saw their mother bow.
Riva #1, Bechor Shor: Since at least two females are included, it says va'Tishtachavenah, even though also the sons bowed. 2
Riva #2, Hadar Zekenim, R. Chaim Palti'el: Sometimes the verse first discusses the first matter mentioned (in this case, the maidservants), and sometimes the latter matter.
Oznayim la'Torah: The Torah writes the word in connection with the maidservants, who are accustomed to prostrating themselves and everyone takes their cue from them as to how it is done.
Malbim: The maidservants' sons were minors, and did not bow. Some of Leah's sons were adults, e.g. Reuven and Shimon, and bowed. 3
Ha'amek Davar: The maidservants bowed together; their sons were secondary to them. Leah was surrounded by her six sons, and they were noticed more, so it is written in the masculine.
Riva, Hadar Zekenim, Bechor Shor and R. Chaim Palti'el reject this, for Yaakov bowed! (I also find it difficult to say that Bnei Bilhah and Zilpah considered themselves more important than their mothers - PF.)
He gives other examples of this. (We must say that also the sons bowed, according to all those who say that Binyamin was the only Shevet that did not bow to Esav, and this is why (a) the first king (Sha'ul) was from Binyamin (Midrash Shmuel 14, Pnei David (Emor 5) citing Rama mi'Pano); (b) Mordechai (from Binyamin) did not bow to Haman (Pesikta Zutresa Esther 3:4, Targum Sheni Esther 3:3); (c) the Mikdash was built in Binyamin's portion (refer to 32:23:1.01:4* - PF.))
Yaakov's sons were very mature! (They were Giborim and Tzadikim like Yaakov (Bereishis Rabah 74:13), and [each] took a rock that all of Lavan's men were unable to move (Tanchuma on 32:7)! They [all] wisely answered Shechem's request for Dinah (34:13), less than two years later. Why would they not follow their father's instructions to bow?! Perhaps since they were minors, Esav would not be angry if they do not bow, so there was no reason for them to bow to a Rasha. (PF)
