What oath does a debtor take when claiming repayment of a verbal loan?
For a verbal (oral) loan, if the debtor claims he paid, he takes a shvuat hesset — a Rabbinic-level oath — and is freed of responsibility, since repayment of an oral loan need not be done before witnesses.
Question 2
Can a lender collect a promissory-note debt from property that was sold to third parties?
A promissory note is public, so purchasers are expected to have investigated whether the property they were buying was under lien. The creditor may expropriate it from them.
Question 3
By Torah law, can a creditor collect from movable property inherited by heirs?
By Torah law, only landed property is under lien to creditors. Movable property inherited by heirs is not liened. However, the Geonim enacted that creditors may collect from movables of heirs.
Question 4
When a borrower writes a promissory note himself and delivers it to the lender in front of witnesses, what is its status?
If the borrower writes the note himself and delivers it to the lender before witnesses who read it, it is a valid promissory note, provided the script cannot be forged.
Question 5
What did the later Geonim ordain regarding creditors and heirs?
The Geonim ordained that creditors may collect debts from the movable property of heirs, extending beyond the Torah's limitation to landed property only. This is universally practiced.