Honor killing and violence is in accordance with Islamic mores and tradition. A recent survey showed that 91 percent of honor killings worldwide are committed by Muslims, and 84 percent of honor killings in the United States were done by Muslims. This is no surprise. A manual of Islamic law approved by Al-Azhar, the most respected authority in Sunni Islam, stipulates that “retaliation is obligatory…against anyone who kills a human being purely intentionally and without right.” However, “not subject to retaliation” is “a father or mother (or their fathers or mothers) for killing their offspring, or offspring’s offspring.” In other words, Islamic law sets no penalty for a parent who kills his child. Also, the legal codes of Jordan, Syria, and other Muslim countries have substantially reduced penalties for honor murders as compared to other murders, and Islamic clerics have resisted efforts to stiffen penalties for honor killings. (source)

From one of the most important English-language sources for the content of Islamic law: Reliance of the Traveller: A Classic Manual of Islamic Sacred Law:

It is certified by Al-Azhar University as a translation that “corresponds to the Arabic original and conforms to the practice and faith of the orthodox Sunni Community…”:

Note that this Sharia manual also garners respect in the USA. Dr. Alan Godlas, Associate Professor of Religion at the University of Georgia, calls it a “carefully translated manual of the proper practice of Islam (shari’a) according to the Shafi’i madh’hab. It has been an essential book in the library of any serious English speaking Muslim or scholar of Islam since its publication in 1991.”

In Book O, titled “Justice,” in section 1, “Who is Subject to Retaliation for Injurious Crimes,” section o1.1 reads, “Retaliation is obligatory … against anyone who kills a human being purely intentionally and without right…”:

However, o1.2 clarifies (above) that “The following are not subject to retaliation” and then lists — after the lovely, egalitarian “Muslim for killing a non-Muslim” and “Jewish or Christian subject … for killing an apostate” — “(4) a father or mother (or their fathers or mothers) for killing their offspring, or offspring’s offspring”: