"It is narrated from Asma bint Abu Bakr who said, "I was the fourth of four wives of al-Zubair. Whenever he would reprimand one of us, he would break off a branch from the wooden clothes hangers and beat her with it until he broke it over her."
There are also hadith that show companions used sticks and broke them during the "hitting" - so when Muslims say the hitting should be "Light" - that simply means it should not be be so harsh as to break bones, tear skin, or cause sever bruising. (Wow! Islam really improved the lot of women
Really? Will you be able to quote any of those? It would be helpful
(Tahtheeb al-athar, Tabari)
But bear in mind that any Muslim you quote this to will throw it back and say 'Ah, but it's not a hadith of the prophet and not from Bukhari or Muslim. Though of course if some Tom, Dick or Harry said something they like in some obscure book that no-one's heard of - then it will suddenly become acceptable evidence
You can always ask them why Mo didn't do anything about it if it was illegal to hit them that way. I stumbled across this hadith yesterday which is a pretty good one as it shows the man can beat his wife over the stupidest things-
Sunan Abu Dawud
Book 13, Number 2453:
Narrated AbuSa'id al-Khudri:
A woman came to the Prophet (peace_be_upon_him) while we were with him.
She said: Apostle of Allah, my husband, Safwan ibn al-Mu'attal, beats me when I pray, and makes me break my fast when I keep a fast, and he does not offer the dawn prayer until the sun rises.
He asked Safwan, who was present, about what she had said. He replied: Apostle of Allah, as for her statement "he beats me when I pray", she recites two surahs (during prayer) and I have prohibited her (to do so).
He (the Prophet) said: If one surah is recited (during prayer), that is sufficient for the people.
(Safwan continued:) As regards her saying "he makes me break my fast," she dotes on fasting; I am a young man, I cannot restrain myself.
The Apostle of Allah (peace_be_upon_him) said on that day: A woman should not fast except with the permission of her husband.
(Safwan said:) As for her statement that I do not pray until the sun rises, we are a people belonging to a class, and that (our profession of supplying water) is already known about us. We do not awake until the sun rises. He said: When you awake, offer your prayer.