'Pledge' in the Bible

And he said, I will send thee a kid of the goats from the flock. And she said, Wilt thou give me a pledge, until thou send it?

And he said, What pledge shall I give thee? And she said, Thy signet, and thy lace, and thy staff which is in thy hand. And he gave it her, and went in to her; and she conceived by him.

And Judah sent the kid of the goats by the hand of his friend the Adullamite, to receive the pledge from the woman's hand; but he found her not.