Qualities of the Righteous Wife (Surah An-Nisa' 4:34)

Allah said,

Therefore, the righteous women, are Qanitat,  obedient to their husbands, as Ibn `Abbas (Radhi Allahu Anhu) and others stated.

and guard in the husband's absence.  As-Suddi and others said that it means she protects her honor and her husband's property when he is absent, and Allah's statement,

what Allah orders them to guard.  means, the protected [husband] is the one whom Allah protects. Ibn Jarir recorded that Abu Hurayrah (Radhi Allahu Anhu)  said that the Messenger of Allah  (Sallallahu Alayhi wa Sallam) said,

The best women is she who when you look at her, she pleases you, when you command her she obeys you, and when you are absent, she protects her honor and your property.

Then, the Messenger of Allah (Sallallahu Alayhi wa Sallam) recited the Ayah,

Men are the protectors and maintainers of women,(Surah An-Nisa: 4:34 (first part)  of Allah and said,

If the woman prayed her five daily prayers, fasted her month, protected her chastity and obeyed her husband, she will be told, 'Enter Paradise from any of its doors you wish.'

Reference: Tafsir ibn Kathir (abridged) English version.