כִּֽי־יִמָּכֵ֨ר לְךָ֜ אָחִ֣יךָ הָֽעִבְרִ֗י א֚וֹ הָֽעִבְרִיָּ֔ה וַעֲבָֽדְךָ֖ שֵׁ֣שׁ שָׁנִ֑ים וּבַשָּׁנָה֙ הַשְּׁבִיעִ֔ת תְּשַׁלְּחֶ֥נּוּ חָפְשִׁ֖י מֵעִמָּֽךְ׃
Si un Hébreu, ton frère, ou une femme hébreue te sont vendus, ils te serviront six ans; et la septième année tu les renverras, libres, de chez toi.
Mishnah Kiddushin
A Hebrew slave is acquired by money and by document; And acquires himself by years, by Jubilee, and by deduction from the purchase price. A Hebrew maidservant is greater in that she acquires herself by ‘signs [of physical maturity]’. He whose ear is bored is acquired by boring, and acquires himself by Jubilee or his master's death.