Sefer HaChinuch ספר החינוך

To not allow a gentile to work a Hebrew slave sold to him: That we not allow a gentile that dwells in our lands work a Hebrew slave, who sold himself to him, with oppressive work — as it is stated (Leviticus 25:53), “he shall not subjugate him oppressively in your eyes.” And we should not say, “Since this Hebrew sinned against himself and sold himself to the gentile, let us leave him to suffer all the work. And they said in Sifra, Behar, Chapter 8:8), “‘He shall not subjugate him oppressively in your eyes’ — you are only commanded ‘in your eyes.’” [This is] meaning to say that we are not obligated to look for it and to enter the house of the gentile to see if he has him work oppressively or not; but rather any time we see the thing, we have to prevent it from him.

The root of this commandment is revealed to all who see the sun. Its laws are included in its essence.

And [it] is practiced by males and females at the time that our hand is powerful over the nations, that we have the power with us over them to command them to do a thing or not to do it. And one who transgresses it and saw the gentile make the Israelite work with oppressive work — and he has the power in his hand to prevent him — but he does not prevent him, violates this negative commandment. But we do not administer lashes for it, since there is no act [involved] with it.