2 Samuel 24:23

And Araunah said unto David, Let my lord the king take and offer up what seemeth good unto him: behold, here be oxen for burnt sacrifice, and threshing instruments and other instruments of the oxen for wood.

And the king said unto Araunah, Nay; but I will surely buy it of thee at a price: neither will I offer burnt offerings unto the LORD my God of that which doth cost me nothing. So David bought the threshingfloor and the oxen for fifty shekels of silver.