Al circumcision is taken from the Arabic kha-ta-na, which is cut off. Some linguists specializing lafadz circumcision for men, while for women called khifadh. 
As for in terms of religious law, intended to cut the skin that covers the head of the penis for men, or cut of meat that stands out above the vagina, also called the clitoris for women. 
Circumcision, PROPHET IBRAHIM ALAIHISSALLAM Shari'a
Circumcision is one of the teachings which Allaah revealed to Prophet Ibrahim Alaihissallam to be implemented, referred to as "sentence" (commands and prohibitions). He Alaihissallam has run the command completely, so he made Allaah as a role model and the priests the entire universe. In surat al Baqarah Allah Subhanahu wa Ta'ala says:
وإذ ابتلى إبراهيم ربه بكلمات فأتمهن قال إني جاعلك للناس إماما قال ومن ذريتي قال لا ينال عهدي الظالمين
"And (remember) when his Lord tested Abraham with a few sentences (commands and prohibitions), and Abraham fulfilled. He said:" Behold, I will make you a priest for all people. "Ibrahim said:" (And I ask you as well) from progeny ". He said:" I promised (this) is not about those who do wrong. "[al-Baqarah: 124].
Circumcision including nature mentioned in the hadeeth. From Abu Hurayrah, who said:
الفطرة خمس: الختان والاستحداد ونتف الإبط وتقليم الأظفار وقص الشارب
"Five of the nature of circumcision, istihdad (pubic hairs), plucking the armpit hairs, cutting the nails and shave the mustache." 
In the Musnad of Ahmad Ammar ibn Yasir radi 'anhu, who said: "It has been said: the Prophet sallallaahu' alaihi wa sallam:" Most of nature is: rinse his mouth, istinsyaq (sipping water from the nose), shaved his mustache, miswak, cut nails , clean the folds on the body, plucking the armpit hairs, istihdad, circumcision and purification. "
The purpose of nature is, the culprit disifati with nature that has been Allaah fitrahkan servant thereof, and He has been advised by the perfection of their nature. Basically, these properties do not require command Shari'a in its execution, because these things are desirable and appropriate by nature.
According to Ibn al-Qayyim rahimahullah, nature was divided in two. Nature relating to heart and he is makrifat to Allaah, to love and mendahulukanNya from another. And second, Amaliah nature and the things he mentioned above. The first purify the soul and cleanse the heart, while the second purify the body, and both help each other and reinforce each other. And the basic nature of the body is circumcision. 
Circumcision originated from the teachings of the Prophet Ibrahim, whereas previously no one circumcision . In the hadith narrated by Abu Hurayrah, that the Prophet sallallaahu 'alaihi wa sallam said: "Ibrahim circumcision after eighty years old." 
After the Prophet Ibrahim alaihi wa sallam, and the sunna circumcision tradition continues for all the apostles and their followers, to the al-Masih, that he also circumcision. People do not deny Christians recognize and circumcision, as they acknowledge illicit pork, illicit money income Sabbath, they admit pray facing Shakhrah (a stone as a mecca Masdjid Jews in Al Aqsa, Pen), and they admit to not fasted fifty days , is fasting is they call the "big fast". 
Wisdom And Benefits of Circumcision 
1. Circumcision is honor Shari'a which Allaah reserved for servants, would enhance the beauty and inner Zahir, Hanif father perfected religion of the prophets and apostles, as the ancestor of the descendants of Ishmael and Isaac, he was the Prophet Abraham. Circumcision is a dye and a sign of Allaah towards His servants. Allaah says:
صبغة الله ومن أحسن من الله صبغة
"Shibghah God. And who better shibghahnya than God?" [Al-Baqarah: 138].
2. As a sign of 'ubudiah to Allaah, as formerly, that gives a sign in the ear or body in my family as a sign of servitude slaves themselves to the employer. If slaves ran away from her employer, she returned to him through an intermediary such signs. So there is no denying, anyone who has circumcision by cutting the skin, meaning he has thrall himself to Allaah, so everyone knows, whoever is doing circumcision, meaning he is the servant of Allaah.
3. Circumcision represents purity, cleanliness and decoration for His servants who hanif.
4. By circumcision-especially a woman-can neutralize lust. If left circumcision, it will align with animal behavior. And if cut out, then make him be the same as inanimate objects, have no taste. Therefore, we get, people who do not circumcision, whether he is male or female, not satisfied with `Jima (hiperseks). And conversely, the error when circumcise a woman, can make it cool on men.
5. For women who circumcision can brighten the face and satisfy your partner.
عن أم عطية الأنصارية أن امرأة كانت تختن بالمدينة فقال لها النبي صلى الله عليه وسلم: لا تنهكي فإن ذلك أحظى للمرأة وأحب إلى البعل
"In the hadeeth of Umm` Athiah, that a woman in Medina works as circumcisioner. The Prophet sallallaahu 'alaihi wa sallam said to him: "Do not be spent. Indeed, it will benefit women and more beloved husband "
6. Satan dwells in dirty places, including on the skin that do not circumcision. Satan blew on his cock, which he did not blow at those who has circumcision.
The scholars disagree on this issue, is divided to three opinions.
Opinions First: Circumcision is mandatory for men and women. This opinion is a school of Syafi `iyah , Hanabilah  and partly Malikiyah  may Allaah have mercy, and from today's leading scholars, such as Shaykh al-Albani opinion. 
Second Opinion: Circumcision is Sunnah (mustahab). This opinion is a school of Hanafiyah , the opinion of Imam Malik  and Ahmad, in a history  may Allaah have mercy.
Third Opinion: Circumcision obligatory for men and for women's virtue. This opinion is the one narrated from Imam Ahmad , partly Malikiyah  and Zhahiriyah  may Allaah have mercy.
First opinion theorem, which says circumcision obligatory. They argue with the Book, Sunnah, atsar and reason.
a. Theorem of the Book.
Word of Allaah:
وإذ ابتلى إبراهيم ربه بكلمات فأتمهن ... الأية
"And (remember) when his Lord tested Abraham with a few sentences (commands and prohibitions)." [Al-Baqarah: 124].
Note: In fact, circumcision, including a sentence made by Allaah as a form of examination to the Ibrahim Alaihissallam, as was narrated from Ibn Abbas, and the test, generally applicable in this case mandatory. 
Word of Allaah.
ثم أوحينا إليك أن اتبع ملة إبراهيم حنيفا وما كان من المشركين
"Then We inspired in thee (Muhammad):" Follow the religion of Abraham a hanif ". And he was not among those who associate".
Note: Circumcision including Alaihissallam Abraham teachings, so it was included in the generality order to follow. And the origin of the command is required, until there is another proposition that her turn .
b. Theorem of the Sunnah.
Hadith `Utsaim bin Kulaib, from his father, from his grandfather, that he came to the Prophet sallallaahu 'alaihi wa sallam and said:" I had converted to Islam, "The Prophet said," Get rid of hair from you kufr and circumcision  ".
The words of Allaah sallallaahu 'alaihi wa sallam "circumcision", is the' amr (command); and 'amr, law originally required, it shows the necessity of circumcision. These words he sallallaahu 'alaihi wa sallam to one person, also includes the other, until there is the argument specialism. 
And they also argue, as narrated from Zuhri, who said: "It has been said: the Prophet sallallaahu 'alaihi wa sallam:' He who converted to Islam, then circumcision, despite adults' ."
The words of Allaah sallallaahu 'alaihi wa sallam "then let circumcision", is the' amr; and legal origin 'amr, required by sighat (form provided) on the word he sallallaahu' alaihi wa sallam "Those who converted to Islam", lafadznya general, including men male and female.
c. Atsar Salaf.
From Ibn Abbas radi 'anhu, who said: "Al aqlaf (ie people who have not circumcision), not accepted his prayer and not eaten sembelihannya" .
d. Theorem Aqli.
They argue with the theory and qiyas. In theory, it can be seen from several aspects.
First: Allowed open aurat at circumcision. If circumcision is not mandatory, would not be allowed, because it was not an emergency, nor to seek treatment. 
Second: The skin prick to hold unclean, but a liability when removing impure worship. And there is no way eliminate the skin that, except with circumcision. so it must be a legal law, because what can not be perfect unless an obligation to him, then fall is obligatory .
Third: The parent as the cause of the child to feel pain when circumcised, can cause death if to tetanus, and his father spend his wealth for the cost of physician and treatment. If it is not mandatory, then things are not allowed .
Fourth: Verily with circumcision bring in tremendous pain, not prescribed except for three things: to mashlahat, or punishment, or to perform an obligation. In circumcision is not possible because the first two, so that so that the remaining third, which is for an obligation. 
While istidlal (arguments) with qiyas.
First. Circumcision is cutting a tetanus-prone is prescribed, be required such as cutting the hands of thieves 
Second. Actually circumcision is syari the Muslims, then the law is obligatory as the other Islamic syiar .
Theorem a second opinion, which states circumcision as a sunnah and not mandatory. They argue with the Sunnah.
Hadeeth of Abu Hurayrah, that the Prophet said: "Fitrah there are five, among them circumcision ...." 
Note: The purpose of nature is the sunnah. Therefore, the law of circumcision sunnah and not compulsory. Therefore, circumcision is not equated with compulsory like istihdad (pubic hairs). 
As the coming of the Prophet sallallaahu 'alaihi wa sallam, that he sallallaahu' alaihi wa sallam said: "sunna circumcision for men and for women's virtue" .
Note: This hadeeth become texts in the problems that circumcision is sunnah for men and for women's virtue.
Theorem third opinion, they are more detailing some theorem that says the first opinion, namely that says mandatory circumcision for men and women.
They said, "Circumcision for males is more assertive, because if he does not circumcision, the skin is stretched to the end of the penis to prevent him from purification, whereas women are more mild. The collapse of compulsory for men, and not mandatory for women." 
First. In general, every proposition is not free from criticism, as mentioned rebuttal, any opinions on other opinions by Imam Ibn al-Qayyim rahimahullahn .
Second. The first and third opinions have equality in the law of male circumcision, female circumcision and the law have the same arguments that are equally strong.
Third. Men are required circumcision. That is an opinion jumhur, as contained in the first and third opinions. And this opinion is more reassuring, of the opinion that said female circumcision is sunnah, wallahu a `lam.
While what is described by a second opinion on the hadith of Abu Hurayrah, then can we answer, if we accept their excuse that the meaning of nature is the Sunnah, not to say circumcision is not required. Because there are lafadz Sunnah is obligatory and there are not compulsory. He covers all the meanings contained in the Shari'a. While the distinction between voluntary with mandatory, this is a new term. 
Fourth. While female circumcision is reassuring-I-obligatory, because women are syaqa-iq (your equivalent) with men in law.
The reason that makes the writer states that the law required, because with circumcision, a woman can neutralize lust. It may help to Iffah (honor guard). And maintain the honor is demanded by the Shari'a. As the sanctity of Zahir make it compulsory circumcision of boys, as well as the sanctity of life, making it mandatory for female circumcision. 
Implementation of circumcision is divided into three time. 
First: The time required. That is when someone has entered the age of baligh, when he had been obliged to practice their religion, and is not required before that .
In the hadith, Said bin Jubair said: "Abdullah ibn Abbas was asked 'How old are you when the Prophet sallallaahu' alaihi wa sallam died? ', He replied,' I just circumcision time, and they are not circumcision exception is near baligh '. [ 43]
Second: The recommended time for circumcision. That time itsghar , ie the time when a child is encouraged to pray.
Third: The time allowed. That is all time other than those described above.
The scholars disagree circumcision on the seventh day of birth, whether recommended or dimakruhkan? Most memakruhkan circumcision on the seventh day. Similarly, opinion Hasan Basri, Ahmad and Malik rahimahullah. Their theorem as follows.
First: The absence of texts. Khallal narrated from Ahmad. He asked about infant circumcision? He replied, "Do not know. I did not get one khabar (propositions). "
Second: Tasyabbuh (mimic) with the Jews. I asked Abu Abdillah (ie, Imam Ahmad): "Someone is circumcised on the seventh day?" He memakruhkannya, saying: "It is a Jewish deed. And this is also the reason Hasan and Malik, may Allaah have mercy" .
Some take it to istihbab (recommended), and this opinion Wahab bin Munabbih, by reason of easier and less painful for the baby. While others took to the law of origin, which may. Among the opinion of Ibn Munzir.
Rahimahullah Ibn al-Qayyim said, "Our Shaykh (Ibn Taymiyya) said, 'Abraham circumcise Isaac on the seventh day and circumcise Ishmael when he was about baligh. Be circumcision Ishaq became sunnah (tradition) for the tribes, and also a sunnah circumcision for children Ismail cucunya.Wallahu knows best '. "
PEOPLE THAT DO NOT NEED circumcised
There are four things a person does not need to be circumcised and had fallen in debt to him.
First: Someone who was born in a state already circumcision. People like this do not need to be circumcised again. Similarly, scholars agreement. Only some scholars mutaakhirin (later) said: "It is recommended circumcision knife through the place, because that's what he can do, and the Prophet had said, 'If I command you, then do all you guys." 
Rahimahullah Ibn al-Qayyim said, "Really, these deed makruh. No need to draw closer to Allaah with it. And no need to worship with semisalnya. And sharia refuge from it, because it is a futile act that does not exist faidahnya . Past the knife is not the goal. But as a means to an end. If the goal is achieved, then there is no means for the means. "
Second: If someone can not bear bear the pain when circumcision, for ill or elderly, and so forth. Feared for her misery and weakness continues, then in a state like this, he allowed for no circumcision.
Third: A person converting to Islam as an adult, and therefore he was afraid perish; the law of circumcision fell from him by jumhur.
Fourth: A person who died, while he has not circumcision, it is not necessary circumcision, because circumcision is prescribed when a person is still alive, and it has been lost with the death, then no mashlahat to circumcision. 
Some Missunderstand And Problems Around circumcision
1. Organized a feast circumcision. This Amaliah have no basis of sharia, an act mubadzir, even heretical.
2. Peel some skin around the penis when circumcision, as happened in some countries or regions.
3. Less careful choosing physician or doctor, especially for young girls who can be fatal to his future.
4. Frighten children who will circumcision with stories that are not true and can damage the aqeedah of the child.
5. Lalainya some people in the genitals when circumcision problems. Sometimes, the people whatever they can see big circumcised genitalia, especially of the opposite sex.
Shalallahu wa sallam wa 'ala Muhammadin tasliman katsira, wa akhiru da'wana, al hamdulillahi Rabbil' alamin
[Copied from the Sunnah Edition Magazine 11/Tahun IX/1426H/2005M. Published Foundation Lajnah Istiqomah Surakarta, Address Jl. Solo-Solo Puwodadi Km.8 Selokaton Gondangrejo 57 183, Tel. 0271-761016]
. Arab Lisanul (13/137), Tartibul Qamus (2 / 15)
. Tharhut Tatsrib, Iraqi (2 / 75), Fathul Bari, Ibn Hajar (10/340)
. Narrated by Muslim in the Minhaj (1 / 541) and Bukhari in Bari Fath (10/334)
. HR Ahmad (4 / 264), Ibn Majah, no. 294. Hasan hadeeth. See Sahih Jami `al Albani, no. 5782.
. Fathul Bari, Ibn Hajar (10/339)
. Tuhfatul Maudud, Ibn al-Qayyim, pp. 100.
. Ahkamul Qur'an, Ibn Arabi (1 / 36)
. Fath al-Bukhari in Bari (11/88) and Muslim (7 / 97)
. Tuhfatul Maudud, Ibn Qayim, pp. 98.
. See Tuhfatul Maudud, Ibn Qayim, pp. 46-49.
. Abu Dawud, no. 5271, haditsnya hasan, because of the way a lot. See pedigree or higher, no. 722.
. Al Majmu `, Nawawi (1 / 300)
. Al Inshaf, al Mardawi (1 / 123), al Mubdi `, Ibn Muflih (1 / 103, 104).
. Al Qawanin al Fiqhiyah, Ibn Jizzi, 167, Tharhut Tastrib, al-Iraqi (2 / 75).
. See Tamamul Minnah, al-Albani, pp. 69
. Al Mabsuth, Sarkhasi (1 / 156)
. Al Qawanin al Fiqhiyah, Ibn Jizzi, 167
. Al Inshaf, al Mardawi (1 / 123), al Mubdi `, Ibn Muflih (1 / 104)
. Al Inshaf, al Mardawi (1 / 123), al Mubdi `, Ibn Muflih (1 / 104), and this opinion is strengthened by Ibn Qudama t. See al Mughni (1 / 85).
. Al Fawakih ad Dawani, Nafrawi (1 / 461).
. Al Muhalla, Ibn Hazm (2 / 218) and ascribed by al-Iraqi to the school of Syafi `iyah.
. Fathul Bari, Ibn Hajar (10/342)
. Tuhfatul Maudud, Ibn al-Qayyim, pp. 101.
. Hasan hadeeth. HR Ahmad (3 / 415), Abu Dawood (1 / 148). See Irwa `ul Ghalil, al-Albani (1 / 120).
. Fathul Bari, Ibn Hajar (10/341).
. This hadith is mentioned by Ibn al-Qayyim t and he said: "This hadith, although mursal, but fit for use for reinforcing". See Tuhfatul Maudud, pp. 101.
. Mentioned history by Ibn al-Qayyim in Tuhfah, pp. 119.
. Al Majmu `, Nawawi (1 / 300), Fathul Bari, Ibn Hajar (10/341).
. Tuhfatul Maudud, Ibn al-Qayyim, pp. 103 and Fathul Bari, Ibn Hajar (10/341)
. Tuhfatul Maudud, Ibn al-Qayyim, pp. 103 and Fathul Bari, Ibn Hajar (10/341)
. This Istidlal dinukilkan by Ibn Hajar al Hafidz t of Imam Mawardi. See Bari Fath (10/342)
. Al Mughni, Ibn Qudama (1 / 85). Also mentioned by Ibn al-Qayyim this qiyas in Tuhfatul Maudud, pp. 129.130.
. Tuhfatul Maudud, Ibn al-Qayyim, pp. 103 with little change, and Fathul Bari, Ibn Hajar (10/341).
. Has passed takhrijnya.
. Tuhfatul Maudud, Ibn al-Qayyim, pp. 103 and Nailul Authar, Syaukani (1 / 146).
. HR Ahmad (5 / 75) and Bayhaqi (8 / 325).
. Al Mughni, Ibn Qudama (1 / 85, 86).
. Tuhfatul Maudud, Ibn al-Qayyim, hlm.100-110.
. Tuhfatul Maudud, Ibn al-Qayyim, pp. 108.
. Ahkamul Jirahah at Tibbiyah, Muhammad Mukhtar al Syinqithi, pp. 168.
. Syaukani opinion, that there is no specific time for circumcision. He attribute these opinions to jumhur. Nailul Authar (1 / 144).
. Tuhfatul Maudud, Ibn al-Qayyim, pp. 110.
. Fath al-Bukhari in Bari (11/88).
. Itsghar time, ie when a child's milk teeth replaced by adult teeth.
. Al Fawakih ad Dawani (1 / 461). He told Malik menisbatkannya rahimahullah, Tuhfatul Maudud, Ibn al-Qayyim, pp. 112
. Tuhfatul Maudud, pp. 112.
. Bukhari, no. 7288 and Muslim, no. 1337.
. Tuhfatul Maudud, Ibn al-Qayyim, pp. 120, Tharhut Tatsrib, al-Iraqi (2 / 76).
. See Tuhfatul Maudud, Ibn al-Qayyim, pp. 120-121.