Deuteronomy 15:12
If your relative who is a Hebrew man or a Hebrew woman is sold to you, and [he or she] has served you six years, then in the seventh year you shall send that person [out] {free}.
Jeremiah 34:14
"At [the] end of seven years you must let go each one his fellow countryman, the Hebrew who has been sold to you and who has served you six years, and you must let him go free from you." But your ancestors did not listen to me, and they did not incline their ears.
Leviticus 25:39-41
" 'And if your countryman [who is] with you becomes poor, and he is sold to you, {you shall not treat him as a slave}.
Exodus 21:2-6
'If you buy a Hebrew slave, he will serve six years, and in the seventh he will go out as free for nothing.
Deuteronomy 15:1
"At the end of seven years you shall grant remission of debt.
John 8:35-36
And the slave does not remain in the household {forever}; the son remains {forever}.