Ruth 4:6

I thought to disclose it to you, saying, 'Buy it before those who sit here, and before the elders of my people.' If you will redeem it, redeem it; but if you will not redeem it, then tell me, that I may know. For there is no one to redeem it besides you; and I am after you." He said, "I will redeem it.

Then Boaz said, "On the day you buy the field from the hand of Naomi, you must buy it also from Ruth the Moabitess, the wife of the dead, to raise up the name of the dead on his inheritance.

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

So the near kinsman said to Boaz, "Buy it for yourself." He took off his shoe.