5 If brothers are living together and one of them, at his death, has no son, the wife of the dead man is not to be married outside the family to another man: let her husband's brother go in to her and make her his wife, doing as it is right for a brother-in-law to do. 6 Then the first male child she has will take the rights of the brother who is dead, so that his name may not come to an end in Israel. 7 But if the man says he will not take his brother's wife, then let the wife go to the responsible men of the town, and say, My husband's brother will not keep his brother's name living in Israel; he will not do what it is right for a husband's brother to do. 8 Then the responsible men of the town will send for the man, and have talk with him: and if he still says, I will not take her; 9 Then his brother's wife is to come to him, before the responsible men of the town, and take his shoe off his foot, and put shame on him, and say, So let it be done to the man who will not take care of his brother's name. 10 And his family will be named in Israel, The house of him whose shoe has been taken off. 11 If two men are fighting, and the wife of one of them, coming to the help of her husband, takes the other by the private parts; 12 Her hand is to be cut off; have no pity on her.
Matthew Henry's Commentary on Deuteronomy 25:5-12
Commentary on Deuteronomy 25:5-12
(Read Deuteronomy 25:5-12)
The custom here regulated seems to have been in the Jewish law in order to keep inheritances distinct; now it is unlawful.