לֹא־יִקְשֶׁ֣ה בְעֵינֶ֗ךָ בְּשַׁלֵּֽחֲךָ֙ אֹת֤וֹ חָפְשִׁי֙ מֵֽעִמָּ֔ךְ כִּ֗י מִשְׁנֶה֙ שְׂכַ֣ר שָׂכִ֔יר עֲבָֽדְךָ֖ שֵׁ֣שׁ שָׁנִ֑ים וּבֵֽרַכְךָ֙ יְהוָ֣ה אֱלֹהֶ֔יךָ בְּכֹ֖ל אֲשֶׁ֥ר תַּעֲשֶֽׂה׃ (פ)
It shall not seem hard unto thee, when thou lettest him go free from thee; for to the double of the hire of a hireling hath he served thee six years; and the LORD thy God will bless thee in all that thou doest.
Read halakhic rulings (Jewish law) on Deuteronomy 15:18: and classical halakhic sources.