Parashas Behar · Aliyah 6 · Passuk 25:42
Chabad.org — English translation + Rashi
Torah Temimah cites Sifra (Torat Kohanim).
English: “They shall not be sold in the manner of a slave’s sale.” That one may not stand him on the auction block.
Classical derasha (Sifra).
An eved ivri may not be sold by public auction or in the demeaning manner used for permanent slaves.