'Pledge' in the Bible

He said, "I will send you a young goat from the flock." She said, "Will you give me a pledge, until you send it?"

He said, "What pledge will I give you?" She said, "Your signet and your cord, and your staff that is in your hand." He gave them to her, and came in to her, and she conceived by him.

Judah sent the young goat by the hand of his friend, the Adullamite, to receive the pledge from the woman's hand, but he didn't find her.