Boaz said, “Very well, if you buy the field from Naomi, then you are also buying Ruth, the Moabite widow, so that the field will stay in the dead man's family.”
Then Judah said to Er's brother Onan, “Go and sleep with your brother's widow. Fulfill your obligation to her as her husband's brother, so that your brother may have descendants.”
“Teacher,” they said, “Moses said that if a man who has no children dies, his brother must marry the widow so that they can have children who will be considered the dead man's children.
“Teacher, Moses wrote this law for us: ‘If a man dies and leaves a wife but no children, that man's brother must marry the widow so that they can have children who will be considered the dead man's children.’
But if the dead man's brother does not want to marry her, she is to go before the town leaders and say, ‘My husband's brother will not do his duty; he refuses to give his brother a descendant among the people of Israel.’