Besides what I already posted from Surah 9 a couple of posts ago, it's in the Hadiths.The Truth said:Prove it.Snowbear said:In most Islam-ruled societies, people who convert from Islam are executed.
Here's one which cites a verse in the Quran, stating those who become Muslim then leave it and become troublemakers are considered combatants... They should be killed or crucified, banished from the land, have their hands and feet cut off, allowed to bleed until dead, not given water until they're dead, have their eyes branded....
90. Book of those of the People of Unbelief and Apostasy who wage war
I. The Prophet, may Allah bless him and grant him peace, did not cauterise the combatants of the apostates until they died
6418. Abu Qilaba related from Anas that the Prophet, may Allah bless him and grant him peace, cut off [the hands and feet} of the 'Uranis and then did not cauterise them until they died."
II. Not giving water to apostate combatants until they die
6419. Abu Qilaba related that Anas said, "A group of 'Ukl came to the Prophet, may Allah bless him and grant him peace, and they stayed in the Suffa. They disliked Madina snd they said, 'Messenger of Allah, get us some milk.' He said, 'I can see nothing else for you except to go to the camels of the Messenger of Allah.' They went to them and drank of their milk and urine until they were healthy and plump. Then they killed the herdsman and stole the camels.' Someone come to the Prophet, may Allah bless him and grant him peace, to ask for help and he sent men after them in pursuit. It was well into the day when they were brought and he ordered that iron bars be heated up and they were placed in their eyes, and their hands and feet were cut off and not cauterised. Then they were left at al-Harra. They asked for water, but were not given water until they died.
Abu Qilaba said, "They stole and killed and fought Allah and His Messenger."
III. The Prophet, may Allah bless him and grant him peace, branding the eyes of the combatants
6420. Abu Qilaba related from Anas ibn Malik that a group of 'Ukl or 'Urayna but I only know that he said from 'Ukl came to Madina and the Prophet, may Allah bless him and grant him peace, commanded some milk camels for them and told them to go out and drink their milk and urine. They drank it until they recovered and killed the herdsman and stole the camels. The Prophet, may Allah bless him and grant him peace, heard in the morning and sent men to pursue them. When it was well into the day, they were brought and he commanded that their hands and feet be cut off and their eyes branded. They were cast into al-Harra. They asked for water but were not given water."
Abu Qilaba said, "Those people stole, killed and disbelieved after having believed and fought Allah and His Messenger."
The Sahih Bukhari says several times that Muslims who leave Islam are to be executed:The words of the Almighty,
"The reprisal against those who wage war on Allah and His Messenger, and go about the earth corrupting it, is that they should be killed or crucified, or have their alternate hands and feet cut off, or be banished from the land." (5:33)
6417. Abu Qilaba al-Jarmi related that Anas said, "A group from 'Ukl came to the Prophet, may Allah bless him and grant him peace, and became Muslim. They disliked Madina and the Prophet, may Allah bless him and grant him peace, ordered them to go out to the zakat camels and drink their milk and urine. They did that and then regained their health. Then they apostatised and killed the herdsman and stole the camels. The Prophet sent [some people] in pursuit of them and they were brought and their hands and feet were cut off and their eyes gouged out and then they were not cauterised until they died." "The reprisal against those who wage war on Allah and His Messenger, and go about the earth corrupting it, is that they should be killed or crucified, or have their alternate hands and feet cut off, or be banished from the land." (5:33)
I. The Prophet, may Allah bless him and grant him peace, did not cauterise the combatants of the apostates until they died
6418. Abu Qilaba related from Anas that the Prophet, may Allah bless him and grant him peace, cut off [the hands and feet} of the 'Uranis and then did not cauterise them until they died."
II. Not giving water to apostate combatants until they die
6419. Abu Qilaba related that Anas said, "A group of 'Ukl came to the Prophet, may Allah bless him and grant him peace, and they stayed in the Suffa. They disliked Madina snd they said, 'Messenger of Allah, get us some milk.' He said, 'I can see nothing else for you except to go to the camels of the Messenger of Allah.' They went to them and drank of their milk and urine until they were healthy and plump. Then they killed the herdsman and stole the camels.' Someone come to the Prophet, may Allah bless him and grant him peace, to ask for help and he sent men after them in pursuit. It was well into the day when they were brought and he ordered that iron bars be heated up and they were placed in their eyes, and their hands and feet were cut off and not cauterised. Then they were left at al-Harra. They asked for water, but were not given water until they died.
Abu Qilaba said, "They stole and killed and fought Allah and His Messenger."
III. The Prophet, may Allah bless him and grant him peace, branding the eyes of the combatants
6420. Abu Qilaba related from Anas ibn Malik that a group of 'Ukl or 'Urayna but I only know that he said from 'Ukl came to Madina and the Prophet, may Allah bless him and grant him peace, commanded some milk camels for them and told them to go out and drink their milk and urine. They drank it until they recovered and killed the herdsman and stole the camels. The Prophet, may Allah bless him and grant him peace, heard in the morning and sent men to pursue them. When it was well into the day, they were brought and he commanded that their hands and feet be cut off and their eyes branded. They were cast into al-Harra. They asked for water but were not given water."
Abu Qilaba said, "Those people stole, killed and disbelieved after having believed and fought Allah and His Messenger."
Volume 4, Book 52, Number 259:
Narrated Abu Huraira:
Allah's Apostle sent us in a mission (i.e. am army-unit) and said, "If you find so-and-so and so-and-so, burn both of them with fire." When we intended to depart, Allah's Apostle said, "I have ordered you to burn so-and-so and so-and-so, and it is none but Allah Who punishes with fire, so, if you find them, kill them."
Volume 4, Book 52, Number 260:
Narrated Ikrima:
Ali burnt some people and this news reached Ibn 'Abbas, who said, "Had I been in his place I would not have burnt them, as the Prophet said, 'Don't punish (anybody) with Allah's Punishment.' No doubt, I would have killed them, for the Prophet said, 'If somebody (a Muslim) discards his religion, kill him.' "
Narrated Abu Huraira:
Allah's Apostle sent us in a mission (i.e. am army-unit) and said, "If you find so-and-so and so-and-so, burn both of them with fire." When we intended to depart, Allah's Apostle said, "I have ordered you to burn so-and-so and so-and-so, and it is none but Allah Who punishes with fire, so, if you find them, kill them."
Volume 4, Book 52, Number 260:
Narrated Ikrima:
Ali burnt some people and this news reached Ibn 'Abbas, who said, "Had I been in his place I would not have burnt them, as the Prophet said, 'Don't punish (anybody) with Allah's Punishment.' No doubt, I would have killed them, for the Prophet said, 'If somebody (a Muslim) discards his religion, kill him.' "
Volume 9, Book 83, Number 17:
Narrated 'Abdullah:
Allah's Apostle said, "The blood of a Muslim who confesses that none has the right to be worshipped but Allah and that I am His Apostle, cannot be shed except in three cases: In Qisas for murder, a married person who commits illegal sexual intercourse and the one who reverts from Islam (apostate) and leaves the Muslims."
The mighty Wikki makes a pretty strong statement about it...Narrated 'Abdullah:
Allah's Apostle said, "The blood of a Muslim who confesses that none has the right to be worshipped but Allah and that I am His Apostle, cannot be shed except in three cases: In Qisas for murder, a married person who commits illegal sexual intercourse and the one who reverts from Islam (apostate) and leaves the Muslims."
All five major schools of Islamic jurisprudence agree that a sane male apostate must be executed. A female apostate may be put to death, according to some schools, or imprisoned, according to others.
There's plenty more, but I'm tired now...