"With regard to the ENSLAVING OF CAPTIVES, the author of the Hidayah says: "The Imam, with respect to captives, has it in his choice to slay them, because the Prophet put captives to death, and also because slaying them terminates wickedness; or if he choose, he may make them slaves, because by enslaving them the wickedness of them is remedied, and at the same time the Muslims reap an advantage; or, if he please, he may release them so as to make, them freemen and Zimmis, according to what is recorded of 'Umar; but it is not lawful so to release the idolaters of Arabia, or apostates. It is not Lawful for the Imam to return the captives to their own country, as this would be strengthening the infidels against the Muslims. If captives become Muslims let not the Imam put them to death because the wickedness of them is hereby remedied without slaying them; but yet he may Lawfully make them slaves, after their conversion, because the reason for making them slaves (namely, their being secured within the Muslin territory) had existence previous to their embracing the faith it is otherwise where Infidels become Muslims before their capture, because then the reason for making them slaves did not exist previous to their conversion. It is not lawful to release infidel captives in exchange for the release of Muslim captives from the infidels. According to the two disciples, this is lawful (and such also is the opinion of ash-Shafi'i) because this produces the emancipation of Muslims, which is preferable to slaying the infidels or making them slaves. The argument of Imam Abu Hanifah is that such an exchange is an assistance to the infidels, because those captives will again return to fight the Muslims, which is a wickedness, and the prevention of this wickedness is preferable to effecting the release of the Muslims, since, is they remain in the hands of the infidels, the injury only affects them, and does not extend to the other Muslims, whereas the injury attending the release of infidel captives extends to the whole body of Muslims. An exchange for property (that is, releasing infidel prisoners in return for property) is also unlawful as this is assisting the infidels, as was before observed, and the same is mentioned in the Mazhabu 'l-Mashkur. In the Sairu 'l-Kabir it is asserted that an exchange of prisoners for property may be made where the Muslims are necessitous, because the Prophet released the captive taken at Badr for a ransom. If a captive become a Muslim in the hands of the Muslims, it is not lawful to release and send him back to the infidels in return for their releasing a Muslim who is a captive in their hands, because no advantage can result from the transaction. If, however, the converted captive consents to it, and there be no apprehension of his apostatizing, in this case the releasing of him in exchange for a Muslim captive is a matter of discretion. It is not lawful to confer a favour upon captives by releasing them gratuitously, that is, without receiving anything in return, or their becoming Zimmis, or being made slaves. Ash-Shafi'i says that showing favour to captives in this way is lawful, because the Prophet showed favor in this way to some of the captives taken at the battle of Badr. The arguments of the Hanafi doctors upon this are two-fold: First, it is said in the Qur'an, 'Slay idolaters wherever ye find them'; secondly, the right of enslaving them is established by their being conquered and captured, and hence. it is not lawful to annul that right without receiving some advantage in return, in the same manner as holds with respect to all, plunder; and with respect to what ash-Shafl'i relates that the Prophet showed favour in this way to some of the captives taken at the battle of Badr, it is abrogated by the text of the Qur'an already quoted."