The Hebrew word ga’al means "to restore something to its original or proper state." The noun form of this Hebrew root (go’el) refers to a close relative who will fix what is wrong.
This relative's duties included:
redeeming a kinsman's property to keep it in the family (see Ruth 4:1–4; Jeremiah 32:6–15);
searching for the kinsman's murderer and bringing him to justice (Numbers 35:19); and
marrying his brother's widow to produce a male heir for the estate of the dead brother (Deuteronomy 25:5–10; see Genesis 38:6–30; Ruth 4:9–10).