(9) باب وُجُوبِ الإِحْدَادِ فِي عِدَّةِ الْوَفَاةِ وَتَحْرِيمِهِ فِي غَيْرِ ذَلِكَ إِلاَّ ثَلاَثَةَ أَيَّامٍ
Humaid b. Nafi' narrated two traditions from Umm Salama dealing with collyrium and the other hadith from the wives of Allah's Prophet (ﷺ) except with this that no mention was made of Zainab.
Reference: Sahih Muslim 1488 d
In-book reference: Book 18, Hadith 77
USC-MSA web (English) reference(deprecated numbering scheme): Book 9, Hadith 3542