Musannaf Ibn Abi Shayba 13:339

Zayd ibn al-Hubab narrated to us, from Hammad ibn Salamah, from Iyas ibn Mu'awiyah, who said: If the pledger and the pledgee disagree, the statement is the statement of the pledgee regarding what is between it and its value. If it exceeds that, then the statement is the statement of the pledger.