'Pledge' in the Bible

He replied, "I'll send you a young goat from the flock." She asked, "Will you give me a pledge until you send it?"

He said, "What pledge should I give you?" She replied, "Your seal, your cord, and the staff that's in your hand." So he gave them to her and had sex with her. She became pregnant by him.

Then Judah had his friend Hirah the Adullamite take a young goat to get back from the woman the items he had given in pledge, but Hirah could not find her.

I myself pledge security for him; you may hold me liable. If I do not bring him back to you and place him here before you, I will bear the blame before you all my life.