Now this was the custom in former time in Israel concerning redeeming and concerning exchanging, to confirm all things: a man took off his sandal and gave it to his neighbor, and this was the way of attestation in Israel. Bible

“sandal.” The custom of giving up a sandal when land is bought, sold, or exchanged likely comes from the idea that the right to walk on the land belonged to the person who owned the land, and when a person no longer had a right to walk on the land then he gave up a sandal as tangible proof the land was not his. It also was a clear proof that the deal was done. If someone had your sandal, then everyone knew you agreed to the deal.

Commentary for: Ruth 4:7