Original Verse:
Jeremiah Chapter 34 Verse 14At the end of seven years ye shall let go every man his brother that is a Hebrew, that hath been sold unto thee, and hath served thee six years, thou shalt let him go free from thee: but your fathers hearkened not unto me, neither inclined their ear.

Reference Verses:
Nehemiah Chapter 10 Verse 31and if the peoples of the land bring wares or any grain on the sabbath day to sell, that we would not buy of them on the sabbath, or on a holy day; and that we would forego the seventh year, and the exaction of every debt.
Deuteronomy Chapter 15 Verse 12If thy brother, a Hebrew man, or a Hebrew woman, be sold unto thee, and serve thee six years; then in the seventh year thou shalt let him go free from thee.
Exodus Chapter 21 Verse 2If thou buy a Hebrew servant, six years he shall serve: and in the seventh he shall go out free for nothing.
Deuteronomy Chapter 15 Verse 12-13 [12] If thy brother, a Hebrew man, or a Hebrew woman, be sold unto thee, and serve thee six years; then in the seventh year thou shalt let him go free from thee. [13] And when thou lettest him go free from thee, thou shalt not let him go empty: