Leviticus 25 v44 Both thy bondmen, and thy bondmaids, which thou shalt have, shall be of the heathen that are round about you; of them shall ye buy bondmen and bondmaids. 45 Moreover of the children of the strangers that do sojourn among you, of them shall ye buy, and of their families that are with you, which they begat in your land: and they shall be your possession. 46 And ye shall take them as an inheritance for your children after you, to inherit them for a possession; they shall be your bondmen for ever: but over your brethren the children of Israel, ye shall not rule one over another with rigour.
These people had all the freedoms that we have today except they were not allowed the freedom of religion and the freedom to choose for whom they should work. They could not practice their pagan religion in the land of Israel and they could not take part in the religious life of Israel except if they became proselytes.
Absolute freedom does not exist in any society upon the earth.
These people had freedom of movement and freedom to have families. Both freedoms which the chattel slavery of Islam does not give to any slave as a human right.
In Islam the slave is simply seen as just another form of money and a way of avoiding work. Also as a form of paying for sin or other reparations should the need arise. Just like a bank account. This is a false religion against the bible.