Reference for Ruth 4:7

וְזֹאת֩ לְפָנִ֨ים בְּיִשְׂרָאֵ֜ל עַל־הַגְּאוּלָּ֤ה וְעַל־הַתְּמוּרָה֙ לְקַיֵּ֣ם כָּל־דָּבָ֔ר שָׁלַ֥ף אִ֛ישׁ נַעֲל֖וֹ וְנָתַ֣ן לְרֵעֵ֑הוּ וְזֹ֥את הַתְּעוּדָ֖ה בְּיִשְׂרָאֵֽל׃

Now this was the custom in former time in Israel concerning redeeming and concerning exchanging, to confirm all things: a man drew off his shoe, and gave it to his neighbour; and this was the attestation in Israel.—