Admittedly the grotesquely named practice of so-called 'honour killing' is not exclusively restricted to Muslims, but the cases that have come to light would suggest that it is most widely practised by people of that persuasion. Why this is so is not such a mystery, since the Qur'an and the Sunnah together form the Shari'a, which deals with every aspect of life, including international, constitutional, administrative, criminal, civil, family, and religion. Subsequently, Islamic scholars made legal rulings on the basis of the Shari'a, and these are called the Fiqh. Now the Fiqh recognises four classes of crimes, the most serious of which are called Houdoud.
Houdoud crimes are said to be so serious that they threaten the very existence of Islam per se, and they are to be punished in accordance with the penalties set forth in the Qur'an itself - which is, after all, the so-called inerrant words of 'god' - or the Sunnah - matters which were subsequently laid down by Muhammad, either by his word or deed. Houdoud crimes include adultery, defamation, theft, robbery, rebellion, drunkenness, and apostasy, and some are punishable by death - specifically adultery, which is classed alongside apostasy. As a general rule the death penalty is to be carried out by the sword, but for adultery the woman is to be stoned to death as this is slower and more painful for her - and a greater deterrent to other women.
However, Sharif Kanaana, professor of anthropology at Birzeit University has stated that 'honour killing' is:
A complicated issue that cuts deep into the history of Arab society. .. What the men of the family, clan, or tribe seek control of in a patrilineal society is reproductive power. Women for the tribe were considered a factory for making men. The honor(sic) killing is not a means to control sexual power or behavior(sic). What's behind it is the issue of fertility, or reproductive power.Not only does the Professor make no reference to the Fiqh imposing the death penalty for sexual transgressions, were his explanation that culture rather than religion be blamed for this barbaric practice, a woman who produced only female children should also be killed by the tribe, since she would be a distinct liability by failing in her duty to be 'a factory for making men', especially as these same men readily murder their girl-children when they consider them a burden.
Although the organisation 'Human Rights Watch' declared in 2001 that...
Honor(sic) crimes are not specific to any religion, nor are they limited to any one region of the world. Human Rights Watch has worked on this issue in the Americas, Asia, the Middle East, and North Africa.... the fact remains that the practice is predominantly one practised by Muslims qua Muslims. Furthermore, there is nothing to distinguish the cultural or the religious practices of these people, for both are born out of their collective ignorance and superstition. And irrespective of what anyone says to the contrary, there is no honour is 'honour killings', they are simply another means of men expressing their insecurities, misogyny and control over women - but that's what religion is all about anyway!