I wonder if this position was taken from the Muslim slaver behavior who had been conquering/enslaving Christians for quite a while at that point. Especially as

I wonder if this position was taken from the Muslim slaver behavior who had been conquering/enslaving Christians for quite a while at that point. Especially as Spain was being taken back from Muslim colonizers at that time, and you have lands that had been under Muslim practices (enslaving non-muslims) now having the roles reversed but perhaps the engrained Islamic thought (only enslave non-believers) entrenched. https://en.wikipedia.org/wiki/Saqaliba https://en.wikipedia.org/wiki/Saqaliba