"Fight those who believe not in Allah or the Last Day, nor hold that forbidden which hath been forbidden by Allah and His Messenger, nor acknowledge the religion of Truth, (even if they are) of the People of the Book, until they pay the jizya with willing submission, and feel themselves subdued." - Quran 9:29 (read more)

"Narrated Kurib: the freed slave of Ibn 'Abbas, that Maimuna bint Al-Harith told him that she manumitted a slave-girl without taking the permission of the Prophet. On the day when it was her turn to be with the Prophet, she said, "Do you know, O Allah's Apostle, that I have manumitted my slave-girl?" He said, "Have you really?" She replied in the affirmative. He said, "You would have got more reward if you had given her (i.e. the slave-girl) to one of your maternal uncles." - Sahih Bukhari 3:47:765 (read more)

"Apostasy is of two types: ordinary apostasy and extreme apostasy, for which execution is prescribed. In both cases there is evidence that it is essential to execute the apostate, but the evidence indicating that the sentence of death may be waived if the person repents does not apply to both types of apostasy. Rather the evidence indicates that that is allowed only in the first case – i.e., ordinary apostasy." - Shaykh al-Islam Ibn Taymiyah