Commemorating a tragic childbirth
ויהי בצאת נפשה כי מתה ותקרא שמו בן-אוני ואביו קרא-לו בנימין
As [Rochel’s] life departed (since she was dying), she called [her son’s] name Ben-Oni, [whereas] his father called him Binyamin
The death of Rochel during childbirth was tragic enough on its own. However, it was further marred by what seems to be an awkward case of spousal disagreement. Rochel decides to name her second child the name Ben-Oni, which literally translated seems to mean “the son of my mourning”. Her intent would appear to be to call to mind the fact that this boy was the cause of her death, which caused others to mourn for her. Yaakov had a different name which he intended to call their son, Binyamin, which literally means “the son of [my] right hand”. Yaakov appears to want his son’s name to have a more positive connotation. What exactly was their disagreement? What were they both thinking?
The word “Oni” can also have a more positive meaning. It’s used elsewhere to mean “strength”. According to this, Rochel would be naming her son Ben-Oni, to mean: “the son of my strength”. What could this be referring to? Our Sages inform us of the incredible self-restraint that our foremother Rochel possessed. For seven years she was expecting to marry the perfect husband, Yaakov. He toiled day and night for the opportunity to marry her. When the day finally came, she realized that her father Lavan was trying to trick Yaakov into marrying her sister Leah. His plan wouldn’t work, as Yaakov and Rochel had created a secret code to prevent such switcheroo’s.
However, Rochel realized what a tremendous embarrassment this whole episode would be for Leah, and ended up divulging to her the secret code. As such, Yaakov married Leah instead. Rochel was able to overcome her intense desire to marry Yaakov, and yielded instead to her sister’s feelings. What’s more, she may have never expected to marry Yaakov afterwards, as she knew that the Torah would eventually forbid a man from marrying sisters. Yaakov followed the entire Torah before it was given, and as such she was giving away her dream husband forever.
Yaakov in the end only kept the Torah while living in the land of Israel. Since they were outside it, he was able to marry Rochel as well. It took years for them to have their first son, and now she merited to have a second. As she was dying from childbirth, she decided to name her son in memory of her incredible strength. Ben-Oni testifies to the tremendous self-control she displayed. Why now did she decide to recall such strength? Why didn’t she allude to this by naming her first son Ben-Oni?
Rochel was also calling attention to why she was dying at this moment. This was no coincidence. They were just entering the land of Israel when she went into labor. She understood that she was dying because her husband observed the entire Torah while in the land of Israel. Since he was not allowed to be married to two sisters, and she was the second sister to marry him, Hashem made it her time to die. She understood that her death was because of her incredible strength. If she hadn’t controlled herself and had (understandably) selfishly married Yaakov first, her sister would have been embarrassed, but Rochel would have been the sole wife. She wouldn’t need to die at this point. On her deathbed, she decided to name her son Ben-Oni, to shed light on why she died.
Yaakov knew this was his wife’s intention. However, he was concerned people would misunderstand. Since Ben-Oni could mean “the son of my mourning”, he was worried people would think this was his wife’s true intent. He knew she had a far deeper message to share, and decided to make his son’s name more explicit. He named him Binyomin, meaning “the son of my right hand”. Since the right hand is the symbol of strength, everyone would realize what she meant. She meant for her son’s name to signify the incredible strength she displayed, with the concern for her sister’s feelings.
 Based on Chasam Sofer Al HaTorah to Genesis 35:18
 Genesis loc. cit.
 Ramban ad. loc., from the word אונן. Cf. Rashi ad. loc., who says it means צערי, affliction/pain
 Cf. Rashi ad. loc.
 Genesis 49:3 with Rashi. There, he cites other examples from Isaiah 5:29, 40:26, and Hosea 12:9
 Megillah 13b; Eichah Rabbah Pesikta § 24 (near the end). These two sources disagree if Yaakov gave Rochel the code (the former), or if it was Rochel who gave to Yaakov (the latter). See the latter source which describes the shocking lengths to how far Rochel went to make it appear as if Leah was her
 Leviticus 18:18
 Genesis 32:5 with Rashi; Lekach Tov and Midrash HaGadol ad. loc.
 Ramban to Genesis 26:5
 Ibid to Leviticus 18:25