'Witness' in the Bible

I went out full, and the Lord has sent me back again with nothing; why do you give me the name Naomi, seeing that the Lord has given witness against me, and the Ruler of all has sent sorrow on me?

Now, in earlier times this was the way in Israel when property was taken over by a near relation, or when there was a change of owner. To make the exchange certain one man took off his shoe and gave it to the other; and this was a witness in Israel.