Charles Ellicott Commentary Leviticus 25:45

"Moreover of the children of the strangers that sojourn among you, of them shall ye buy, and of their families that are with you, which they have begotten in your land: and they shall be your possession." — Leviticus 25:45 (ASV)

Moreover of the children of the strangers. — Besides the surrounding nations, the Hebrews are also permitted to obtain their slaves from those strangers who have taken up their dwelling in the Holy Land. By these strangers, the ancient authorities understand those who have been permitted to settle down among the Jews on condition that they submit to the seven commandments given to Noah, but have not embraced Judaism. Hence, the Chaldee Version translates this phrase, “the children of uncircumcised strangers.”

And they shall be your possession. — These, but not the Hebrews, the masters may hold as their absolute property.