Beating of wives

The Quran instructs that men are in charge of women. If the women are to disobey, then a three step process should be taken:

• Advise them
• Forsake them in bed
• Strike them

This is detailed in the Quran:

Quran 4:34
Men are in charge of women by [right of] what Allah has given one over the other and what they spend [for maintenance] from their wealth. So righteous women are devoutly obedient, guarding in [the husband's] absence what Allah would have them guard. But those [wives] from whom you fear arrogance - [first] advise them; [then if they persist], forsake them in bed; and [finally], strike them. But if they obey you [once more], seek no means against them. Indeed, Allah is ever Exalted and Grand.

The third part is what is in contention here. The modern Muslim readings suggest that you are to lightly beat your wife, but that is not what is seen within Islam at the time of Mohammad, specifically Mohammad's wife Aisha. She pointed out that women suffer far more than non-Muslims, as they are allowed to be beaten. Aisha points out that a lady was beaten hard enough that her skin was greener than her clothes. This is not a light beating:

Sahih al-Bukhari 5825
Rifa`a divorced his wife whereupon `AbdurRahman bin Az-Zubair Al-Qurazi married her. `Aisha said that the lady (came), wearing a green veil (and complained to her (Aisha) of her husband and showed her a green spot on her skin caused by beating). It was the habit of ladies to support each other, so when Allah's Messenger (ﷺ) came, `Aisha said, "I have not seen any woman suffering as much as the believing women. Look! Her skin is greener than her clothes!" When `AbdurRahman heard that his wife had gone to the Prophet, he came with his two sons from another wife. She said, "By Allah! I have done no wrong to him but he is impotent and is as useless to me as this," holding and showing the fringe of her garment, `Abdur-Rahman said, "By Allah, O Allah's Messenger (ﷺ)! She has told a lie! I am very strong and can satisfy her but she is disobedient and wants to go back to Rifa`a." Allah's Messenger (ﷺ) said, to her, "If that is your intention, then know that it is unlawful for you to remarry Rifa`a unless `Abdur-Rahman has had sexual intercourse with you." Then the Prophet (ﷺ) saw two boys with `Abdur- Rahman and asked (him), "Are these your sons?" On that `AbdurRahman said, "Yes." The Prophet (ﷺ) said, "You claim what you claim (i.e.. that he is impotent)? But by Allah, these boys resemble him as a crow resembles a crow,"