In Leviticus 25, we learn about the land’s sabbath, the year of jubilee and the kinsman redeemer. In the book of Ruth, Boaz is the kinsman redeemer.
The Lord (to Moses in mount Sinai) Speak to the children of Israel:
The Land’s Sabbath
When you come into the land which I give you, then the land shall keep a sabbath to the Lord. Sow your field and prune your vineyard and gather the harvest for six years. The seventh year shall be a sabbath of rest for the land. You shall neither sow your field nor prune your vineyard. That which grows of its own accord you shall not reap.
The Year of Jubilee
You shall number seven sabbaths of years, seven times seven years; forty and nine years. Then you shall cause the trumpet of the jubilee to sound throughout all your land on the tenth day of the seventh month, on the day of atonement. The fiftieth year shall be set apart as holy. You shall proclaim liberty throughout all the land to all the inhabitants: it shall be a jubilee for you; in the year of jubilee, you shall return every man to his possession (land), and you shall return every man (sold as a slave) to his family. A jubilee shall be that fiftieth year: you shall not sow, nor reap that which grows of itself, nor gather the grapes of your undressed vine.
What shall we eat the seventh year when we shall not sow nor gather? I will command my blessing on you in the sixth year, and it shall bring forth fruit for three years. And you shall sow the eighth year, and eat of old fruit until the ninth year; until her fruits comes in you shall eat of the old store.
In the year of jubilee, every man shall return to his possession, the land of his fathers. The land shall not be sold for ever.
Specific details and situations are addressed regarding the year of jubilee.
Another can redeem the land or redeem the person:
1) must be near of kin of his family
2) must be able
3) must be willing