Deuteronomy 25:9

then his brother’s wife shall come to him in the presence of the elders, and loose his sandal from off his foot, and spit in his face. She shall answer and say, “So shall it be done to the man who does not build up his brother’s house.”

Then shall his brother’s wife come unto him in the presence of the elders, and loose his shoe from off his foot, and spit in his face, and shall answer and say, So shall it be done unto that man that will not build up his brother’s house.