Did Buddhism teach anything about the abhorrence of enslaving another human being, prior to Christianity’s foundation?
That is probably a significant social question.
Buddhism teaches the fundamental idea that no one “owns” anything (living or not). Thus the idea of owning a person would not really come up. But they spoke considerably of how to “rightfully” treat a “servant”. Mostly that involved the basic humanities.
A slave is really just a person that has been entrapped into servitude. Judaism and Christianity speak a great deal of entrapping or more importantly, being entrapped. This was an issue due to the Pharaoh and extended practices of entrapping (still being used today).
In both Christianity and Buddhism (and Judaism) a person *cannot *be enslaved if they truly know God, whether anyone attempts it or not.
Today enslavement occurs through the practice of deception in causing a person to not realize that they are entrapped and are kept insulated from any information that would reveal the truth of it. Such a practice of maintaining deception for such a purpose would be strictly anti-Jesus and I’m sure anti-Buddhist because it would involve inhumane treatment even though the enslaver might not ever be seen or caught.
But neither object, to my knowledge, of agreements to serve unless those agreements might end up enslaving the person by default. That would violate the concern of loving.
I think both would tend to see the violation to be of equal blame between the enslaver and the enslaved as each have ignored Reality.
So even though Jesus would stand more strongly against the idea and insist on something being done, I don’t see a great distinction between their attitudes in general. The Buddhist isn’t allowed to hate anything or even strongly feel passion whereas Jesus and Judaism exercise passion, but in specifically pointed directions.
Jesus is more into “accept what is and cause the good” whereas Gautama was more into “accept what is and go your way”.