Tafsiran Rut 4:7: Tze'enah Ure'enah, Rashi & Ibn Ezra

“This was formerly done in Israel” [4:7]. It was the custom in previous times in Israel in cases of redemption and exchange to validate the transaction, one man would take off the glove of his right hand and give his hand to his friend and this is the sign in Israel to confirm the sale from one to the other. Our sages say that the verse means that in previous times the custom was that if someone sold something to someone else and wanted the sale to be permanent, one of them pulled off his glove and gave his hand to his friend and with this the sale was validated. In the present day, the witnesses take their coat and put it on it to affirm the sale.⁷²Targum, Ruth, 4:7.

Concerning redemption. This is a sale.

"In former times, in ancient days that have passed, as 'the faces' are the first.

And exchange. This is an exchange.

A man would take off his shoe. This is an act of acquisition, just as we acquire title with a scarf in lieu of a shoe. And our Rabbis of blessed memory differed on this matter,⁷Maseches Bava Metzia 47a. as to who gave [the shoe] to whom. Some say that one acquires title with the utensil of the acquirer, and Bo’az gave [his shoe] to the redeemer, and some say that one acquires title with the utensil of the seller, and the redeemer gave [his shoe] to Bo’az.

This was the form of validation in Yisroel. תְּעוּדָה =] the law of testimony.