Deuteronomy 25:5-10

⁵If brethren dwell together, and one of them die, and have no son, the wife of the dead shall not be married without unto a stranger: her husband`s brother shall go in unto her, and take her to him to wife, and perform the duty of a husband`s brother unto her. ⁶And it shall be, that the first-born that she beareth shall succeed in the name of his brother that is dead, that his name be not blotted out of Israel. ⁷And if the man like not to take his brother`s wife, then his brother`s wife shall go up to the gate unto the elders, and say, My husband`s brother refuseth to raise up unto his brother a name in Israel; he will not perform the duty of a husband`s brother unto me. ⁸Then the elders of his city shall call him, and speak unto him: and if he stand, and say, I like not to take her; ⁹then 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 she shall answer and say, So shall it be done unto the man that doth not build up his brother`s house. ¹⁰And his name shall be called in Israel, The house of him that hath his shoe loosed.