Quran says when you can beat your wife:

"Verse 4:34 of the Quran as translated by Ali Quli Qara'i reads:

Men are the managers of women, because of the advantage Allah has granted some of them over others, and by virtue of their spending out of their wealth. So righteous women are obedient, care-taking in the absence [of their husbands] of what Allah has enjoined [them] to guard. As for those [wives] whose misconduct you fear, [first] advise them, and [if ineffective] keep away from them in the bed, and [as the last resort] beat them. Then if they obey you, do not seek any course [of action] against them. Indeed, Allah is all-exalted, all-great."