From an anthropological standpoint, this type of marriage strengthens the ties between both groups (the wife's family or clan and the husband's) and preserves the contract between the two to provide children and continue the alliance.
Such a marriage as Jacob's during the lifetime of the first wife was subsequently prohibited by the Law of Moses (Leviticus 18:18).
[7] John Wesley, founder of Methodism, believed the Levitical law permitted marriage with a deceased wife's sister.
[8][9] Sororate is a custom which is practiced among the Kurds like Levirate marriage: When a man loses his wife before she bears a child or she dies leaving young children, her lineage provides another wife to the man, usually a younger sister with a lowered bride-price.
Both Levirate and Sororate are practiced to guarantee the well-being of children and ensure that any inheritance of land will stay within the family.