Deuteronomy 25:7-10

7 But if the man has no desire to marry his brother's widow, then his brother's widow shall go up to the elders at the gate and say, "My husband's brother refuses to perpetuate his brother's name in Israel; he will not perform the duty of a husband's brother to me."
8 Then the elders of his town shall summon him and speak to him. If he persists, saying, "I have no desire to marry her,"
9 then his brother's wife shall go up to him in the presence of the elders, pull his sandal off his foot, spit in his face, and declare, "This is what is done to the man who does not build up his brother's house."
10 Throughout Israel his family shall be known as "the house of him whose sandal was pulled off."
New Revised Standard Version Bible, copyright 1989, Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.