Aḥmad ibn Yaḥyá al-Balādhurī, The Origins of the Islamic State… (1916)
“ Only a truce was arranged between us, according to which we agreed to give them some wheat and lentils, and they to give us slaves. It is all right to buy their slaves from them or from others." Abu-ʿUbaid from al-Laith ibn-Saʿd:—The latter said, "The terms we made with the Nubians stipulated only that we neither fight against them nor they against us, that they give slaves and we give them their value in terms of food. If they desire, therefore, to sell their wives or children, there is no reason why they should not be bought." ”
