Sahih Muslim
The Book of Marriage (Kitab Al-Nikah)
Book Number: 008 / Hadith Number: 3468
Abu Huraira (Allah be pleased with him) reported Allah's Apostle (may peace be upon him) as saying: He who believes in Allah and the Hereafter, if he witnesses any matter he should talk in good terms about it or keep quiet. Act kindly towards woman, for woman is created from a rib, and the most crooked part of the rib is its top. If you attempt to straighten it, you will break it, and if you leave it, its crookedness will remain there. So act kindly towards women.