Targum do Powtórzonego Prawa 25:9

Then shall his sister-in-law come to him before the sages, and there shall be a shoe upon the foot of the brother-in-law, a heeled sandal whose lachets are tied, the latchets at the opening of the sandal being fastened; and he shall stamp on the ground with his foot; and the woman shall arise and untie the latchet, and draw off the sandal from his foot, and afterward spit before him, as much spittle as may be seen by the sages, and shall answer and say, So is it fit to be done to the man who would not build up the house of his brother.