Deuteronomy 25:5

Respect for the Sanctity of Others

25:5 If brothers live together and one of them dies without having a son, the dead man’s wife must not remarry someone outside the family. Instead, her late husband’s brother must go to her, marry her, and perform the duty of a brother-in-law.

Deuteronomy 25:9

25:9 then his sister-in-law must approach him in view of the elders, remove his sandal from his foot, and spit in his face. She will then respond, “Thus may it be done to any man who does not maintain his brother’s family line!”