The idea of the man beating the wife stems from Chapter 4 verse 34, with many variants in interpretation.
All scholars agree that a women may not be hit on the face, and that there may not be any mark caused by the injury. Some believe that the husband has the right to hit is wife physically as long as he abides by the above regulations. Some scholars follow the view that it is a symbolic action and done by either a a toothbrush or by throwing a folded napkin at her. There is another view amongst scholars who view that the word itself has nothing to do with "hitting" but rather implies separation of the spouses.
Firstly, it is important to realize that the traditional view of "lightly hitting" a spouse is viewed as a symbolic action. It is not used as something of physical harm but rather of emotional nature. The nature of the action speaks for itself rather than implying that physical abuse is a prerequisite for it to be effective. Secondly, the Qur'an mandates that spouses must first leave each others' bed meaning that such an action is done after reflection over the conflict limiting powerful and fleeting emotions such as anger or haste pushing a husband to physically harm his wife. Thus what we have is a cultural expression of extreme discontent and anger over a particular issue, but not a mandate for domestic abuse.
Those who reject the idea of hitting have several evidences by which they reexamining the verse according to the Qur'an and attributed Prophetic sayings, as well as analyzing the Arabic grammar of the word itself. These are surmised as follows
The Qur'an establishes a spousal arrangement based on kindness and love
Al-Qur'an 3:21 said:
And of His signs is that He created for you from yourselves mates that you may find tranquillity in them; and He placed between you affection and mercy. Indeed in that are signs for a people who give thought.
And the Qur'an states indicates that a husband should not deal harshly with his wife
Al-Qur'an 4:19 said:
O ye who believe! Ye are forbidden to inherit women against their will. Nor should ye treat them with harshness, that ye may Take away part of the dower ye have given them,-except where they have been guilty of open lewdness; on the contrary live with them on a footing of kindness and equity. If ye take a dislike to them it may be that ye dislike a something that Allah brings about through it a great deal of good.
The Prophet himself never beat his wives and strongly condemned it
Bukhari said:
How does anyone of you beat his wife as he beats the stallion camel and then embrace (sleep with) her?
Do not beat the female servants of Allah
Some (women) visited my family complaining about their husbands (beating them). These (husbands) are not the best of you.
Whereas
I recommend that you treat women with goodness. The best of you are those who treat their wives the best.
Narrated Mu'awiyah al-Qushayri: "I went to the Apostle of Allah (peace_be_upon_him) and asked him: What do you say (command) about our wives? He replied: Give them food what you have for yourself, and clothe them by which you clothe yourself, and do not beat them, and do not revile them.
This may be all well and good, but to have a convincing case the verse itself needs to be addressed.
The word itself
iḍribūhunna comes from the root
daraba ضرب
It can have many meanings and connotations and is used in the Qur'an many times including
To travel, to get out: 3:156; 4:101; 38:44; 73:20; 2:273
To strike: 2:60,73; 7:160; 8:12; 20:77; 24:31; 26:63; 37:93; 47:4
To beat: 8:50; 47:27
To set up: 43:58; 57:13
To give (examples): 14:24,45; 16:75,76,112; 18:32,45; 24:35; 30:28,58; 36:78; 39:27,29; 43:17; 59:21; 66:10,11
To take away, to ignore: 43:5
To condemn: 2:61
To seal, to draw over: 18:11
To cover: 24:31
To explain: 13:17
For example
57:13 يَوْمَ يَقُولُ الْمُنَافِقُونَ وَالْمُنَافِقَاتُ لِلَّذِينَ آمَنُوا انظُرُونَا نَقْتَبِسْ مِن نُّورِكُمْ قِيلَ ارْجِعُوا وَرَاءكُمْ فَالْتَمِسُوا نُورًا
فَضُرِبَ بَيْنَهُم بِسُورٍ لَّهُ بَابٌ بَاطِنُهُ فِيهِ الرَّحْمَةُ وَظَاهِرُهُ مِن قِبَلِهِ الْعَذَابُ
Pickthall said:
On the day when the hypocritical men and the hypocritical women will say unto those who believe: Look on us that we may borrow from your light! it will be said: Go back and seek for light! Then there will separate them a wall wherein is a gate, the inner side whereof containeth mercy, while the outer side thereof is toward the doom.
Thus the root itself has many meanings and thus this translation is up to view.
This would leave the verse's translation using the word to mean "to seperate" as
[...]as for those women whose animosity or ill-will you have reason to fear, then leave them alone in bed, and then separate; and if thereupon they pay you heed, do not seek a way against them.
And followed by the verse
Al-Qur'an 4:35 said:
And if ye fear a breach between them twain (the man and the wife), appoint an arbiter from his folk and an arbiter from her folk. If they desire amendment Allah will make them of one mind. Lo! Allah is ever Knower, Aware.
The excerpt "desire amendment" is pointed out as a reference to the state of separation as opposed to the reverted meaning of "beating" which makes less sense within the context.
Furthermore, this entire process is begun because of "extreme ill-will" or nushuz. This mention of ill-will amongst spouses is also mentioned later in the Qur'an where the husband is the offender (source of nushuz) wherein the Qur'an states
Al-Qur'an 4:128 said:
If a wife fears ill-treatment (nushuz) or desertion on her husband’s part, there is no blame on them if they arrange an amicable settlement between themselves; and such settlement is best[...]
Within this above verse the wife is encouraged to reconcile which sets a double standard while using the same root word and using the same origin of the conflict (nushuz), thus the translation should logically follow that drb be translated as to separate.
Furthermore, there is another opinion that the breach (nushuz) is very severe. In fact it is described as
The literal meaning of the word is "rebellion". But rebellion against whom and in what sense? We should certainly not think of this in terms the rebellion of the ruled against a ruler in a sultanate or dictatorship and conclude that it consists of the wife disobeying some of the husband's commands. This is because the same word nushuz is used in case of a husband in verse 128 of the same surah 4, where it is said: "If a woman fears nushuz on her husband's part..." So nushûz is something that
can be feared by the husband on the wife's part or by the wife on her husband's part. It cannot therefore be understood in terms of the ruler-ruled relationship. To correctly understand the meaning of the word, it must be noted that both in the verse under consideration and in verse 128 the reference to nushuz is followed by a reference to the break-up of the marriage (see vv. 35, 130). If this context is kept in mind, then it becomes evident that nushuz means the type of behavior on the part of the husband or the wife
which is so disturbing for the other that their living together becomes difficult. ...In short, nushûz is a behavior on the part of one marriage partner which comes out of ill-will and seriously disturbs the other partner.[11]
This has been thought to reference to sexually lewd behavior that was witnessed however with the absence of the stringent requirements for zina (four honorable witnesses seeing the penetration of the vagina) called fahisha mubina. Thus there is a crime enforced by a beating (again following the two roles posted in the very beginning regarding he face and physical marks) as judged and carried out by a competent Shari'ah qadi or judge. Thus the beating is not the sole mandate of the man to decide, judge, and execute as man is often fallible and jealous. But rather one that can be applied equally to both man and women by an objective third party. This is the view expressed by the prominent classical scholar Ibn Rushd, 20th century scholar Muhammad Asad, and contemporary scholar Khaled Abou Fadl though the latter views that the arcane legal practice has since ended since the 10th century and can be found
here)
Edit: By the way many people use Pickthall's translation which employs the word scourge however he himself did not believe that men had the authority to physically hit another women.