Settlement: Stipulating a Condition in a Settlement
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 2182
Whenever a person concludes a settlement with someone with respect to his own property and makes a condition saying, ‘After my death, the property that I settled with you must (for example) be given as a charitable endowment (waqf)’, and the other person accepts this condition, he must act according to the condition.
-Ayatullah Sistani, Practical Laws of Islam, Settlement (Sulh)