Ketubot 19: Unreliable Documentation in Financial Halakhah

Defining and explaining the "shtar amanah" - and why a document of "trust" is not to be believed in terms of monetary transactions. How does one prove payment, however? The documentation for loans ends up being key. It's a commitment to good faith, though it's not binding. Also, a case of witnesses who signed and died before the document was needed. People came and attested to the signatures - that they were the handwriting of the witnesses who had died. But the claim is that they signed under duress. Which complicates matters, of course.