Leviticus 25:44

ועבדך ואמתך אשר יהיו לך BUT THY MAN-SERVANT AND THY MAID-SERVANT WHO MAY BE THINE [SHALL BE OF THE NATIONS THAT ARE ROUND ABOUT YOU] — If you should say, “But if this be so (that I must treat my Jewish servant with so much regard), by whom shall I be served? Over my Jewish servants I have no power; of the Canaanite people I cannot possess any for You have warned me, (Deuteronomy XX 16) “Thou shalt keep alive any soul"! Who then shall serve me?” Then I reply — מאת הגוים OF THE OTHER NATIONS — they may be servants to you. אשר סביבתיכם [THE NATIONS] WHO ARE ROUND ABOUT YOU — not, however, those who live within the boundaries of your land; for with regard to them I have indeed told you, “Thou shalt keep alive no soul” (Sifra, Behar, Section 6 3).

וְעַבְדְּךָ֥ וַאֲמָתְךָ֖ אֲשֶׁ֣ר יִהְיוּ־לָ֑ךְ מֵאֵ֣ת הַגּוֹיִ֗ם אֲשֶׁר֙ סְבִיבֹ֣תֵיכֶ֔ם מֵהֶ֥ם תִּקְנ֖וּ עֶ֥בֶד וְאָמָֽה׃

Both thy bondmen, and thy bondmaids, whom thou shalt have, shall be of the nations that are round about you; of them may you buy bondmen and bondmaids.