Ruling 2317
If a debtor, creditor, and transferee, or one of them, reserves the right to annul the transfer of debt, he/they can annul the transfer according to their agreement.
-Ayatullah Sistani, Practical Laws of Islam, Transfer of Debt (Hawalah)
Transfer of Debt: Reserving the Right to Annul a Debt Transfer
Practical Laws of Islam as per the teachings of Ayatullah Sistani
