Musannaf Ibn Abi Shaybah 24288 — A man who pledges something

Sayyiduna Umar (may Allah be pleased with him) said: If the value of the pledged item is more than the thing for which it was pledged, then with regard to that excess the person (with whom it is pledged) is considered a trustee; and if the value of the pledged item is less, the pledger will pay the remaining value to that person.