An-Nur 24:33 وليستعفف الذين لا يجدون نكاحا حتى يغنيهم الله من فضله والذين يبتغون الكتاب مما ملكت ايمانكم فكاتبوهم ان علمتم فيهم خيرا واتوهم من مال الله الذي اتاكم ولا تكرهوا فتياتكم على البغاء ان اردن تحصنا لتبتغوا عرض الحياة الدنيا ومن يكرههن فان الله من بعد اكراههن غفور رحيم ٣٣

Those who are unable to marry should keep chaste until God gives them enough out of His bounty. If any of your slaves wish to pay for their freedom, make a contract with them accordingly, if you know they have good in them, and give them some of the wealth God has given you. Do not force your slave-girls into prostitution, when they themselves wish to remain honourable, in your quest for the short-term gains of this world, although, if they are forced, God will be forgiving and merciful to them.