Seeing oneself held as a hostage in a place signifies many sins and bad deeds, because on the Day of Resurrection people will be held in pledge because of their evil deeds. At times, seeing a pledge or hostage signifies becoming afflicted by hardship and love.
Seeing something left with oneself as collateral signifies committing injustice and oppression against another person.
Seeing oneself pledge something good in exchange for something bad signifies becoming afflicted by attachment to a contemptible person and a decline in one's own worth.