Responsa על יבמות 211:3

Q. A's heirs demand from B A's Humash (one book of the Pentateuch) which witnesses saw in B's possession. B claims that A deposited the book with him as security for the two marks A owed him. Some of A's heirs admit having heard A say before his death that the book was deposited with B as a pledge. Is a Humash classified as an object which is usually borrowed or hired and regarding which a person is, therefore, not believed when he claims to have received it as a pledge?
A. Throughout the kingdom, Rashi's view is accepted that a Humash is not an object that is usually borrowed or hired. B therefore may take an oath that the book was pledged with him for two marks. However, B should be careful in taking his oath; for, if A did not actually owe him two marks, but promised to give B two marks if the latter effect a reconciliation between A and his son, A became indebted to B only for the latter's wages for the time and effort expended, but not for full two marks.
SOURCES: Pr. 1007.