"He shall not rule over him with rigor in your sight"Leviticus 25:53.

We may not allow a non-Jew who lives under Jewish jurisdiction to order a Jewish bondsman in his service to do unnecessary work while we watch. We may not say, "Since this Jew willingly allowed himself to be sold to this gentile, it is not our concern what the gentile compels him to do," rather we must still prevent the gentile from overtly mistreating his Jewish worker. (We are not, however, required to inquire as to what occurs in the privacy of his home, where we cannot see what transpires.)