This hadeeth comes under the following chapter: IT IS OBLIGATORY TO ABSTAIN FROM ADORNMENT DURING THE 'IDDA PERIOD, BUT MOURNING BEYOND THREE DAYS IS PROHIBITED
Humaid b. Nafi' narrated two traditions from Umm Salama dealing with collyrium and the other hadith from the wives of Allaah's Prophet (sallAllaahu alayhi wa sallam) except with this that no mention was made of Zainab.