Deuteronomy 25:9-10

Loose his shoe As a sign of his resignation of all his right to the woman, and to her husband's inheritance; for as the shoe was a sign of one's power and right, (Psalms 60:8; Psalms 108:9,) so the parting with the shoe was a token of the alienation of such right; and as a note of infamy, to signify that by this disingenuous action he was unworthy to be among free men, and fit to be reduced to the condition of the meanest servants, who used to go barefoot, Isaiah 20:2; Isaiah 20:4. His name That is, his person, and his posterity also. So it was a lasting blot.