67ما كانَ لِنَبِيٍّ أَن يَكونَ لَهُ أَسرىٰ حَتّىٰ يُثخِنَ فِي الأَرضِ ۚ تُريدونَ عَرَضَ الدُّنيا وَاللَّهُ يُريدُ الآخِرَةَ ۗ وَاللَّهُ عَزيزٌ حَكيمٌMuhammad AsadIT DOES NOT behove a prophet to keep captives unless he has battled strenuously on earth.1 You may desire the fleeting gains of this world - but God desires [for you the good of] the life to come: and God is almighty, wise.I.e., as an aftermath of a war in a just cause. As almost always in the Qur'an, an injunction addressed to the Prophet is, by implication, binding on his followers as well. Consequently, the above verse lays down that no person may be taken, or for any time retained, in captivity unless he was taken prisoner in a jihad - that is, a holy war in defence of the Faith or of freedom (regarding which see surah 2, note 167) - and that, therefore, the acquisition of a slave by "peaceful" means, and the keeping of a slave thus acquired, is entirely prohibited: which, to all practical purposes, amounts to a prohitition of slavery as a "social institution". But even with regard to captives taken in war, the Qur'an ordains (in 47:4) that they should be freed after the war is over.