Commentary for Kiddushin 31:4
אמר רב אחא בר יעקב אמר קרא (שמות כא, ז) לא תצא כצאת העבדים אבל נקנית היא כקנין עבדים ומאי ניהו שטר
R'Huna maintained: The master writes it; R'Hisda said: Her father writes it. [Hence] it is well according to R'Huna; but on R'Hisda's view, what can be said? - R'Aha B'Jacob answered: Scripture saith, she shall not go out as the menservants do:<span class="x" onmousemove="('comment',' Ibid. 7; the comparison is with heathen slaves, who go free if their master blinds them or knocks out their teeth (vv. 26f) . Hebrew slaves, however, are not freed, but merely compensated.');"><sup>5</sup></span> [implying,] but she may be acquired as [heathen] menservants are;<span class="x" onmousemove="('comment',' Lit., 'as the acquisition of menservants.'');"><sup>6</sup></span>