If you want to say that god made concessions to man go ahead. He still instructed them in how to hold chattel slaves and implied that they could do so ruthlessly, only restricting them from doing so to eachother.

Leviticus 25:44-46

44 “‘Your male and female slaves are to come from the nations around you; from them you may buy slaves. 45 You may also buy some of the temporary residents living among you and members of their clans born in your country, and they will become your property. 46 You can bequeath them to your children as inherited property and can make them slaves for life, but you must not rule over your fellow Israelites ruthlessly.