Sahih Bukhari Volume 7, Book 67, Hadith 5188

"وَاسْتَوْصُوا بالنِّساءِ خَيرًا، فَإِنَّهُنَّ خُلِقْنَ مِنْ ضِلَعٍ، وَإِنَّ أَعْوَجَ شَيْءٍ فِي الضِّلَعِ أَعلاهُ، فَإِن ذَهَبْتَ تُقِيْمُهُ كَسَرْتَهُ،وَإِنْ تَرَكْتَهُ لَمْ يَزَلْ أَعْوَجَ،فَاسْتَوْصُوْا بِالنِّساءِ خَيرًا"

And I advise you to take care of the women, for they are created from a rib and the most crooked portion of the rib is its upper part; if you try to straighten it, it will break, and if you leave it, it will remain crooked, so I urge you to take care of the women."