Is it permissible, Islamically, for one of the heirs to revoke the inheritance distribution agreement that was reached by mutual consent eight years ago, and from which everyone benefited?

Resolving disputes concerning inheritance issues and shared rights is referred to the Sharia (definition) courts or their representatives, due to their ability to hear from all parties in a dispute and issue an accurate judgment, unlike a Mufti (definition) who hears from only one party.

As for what can generally benefit the questioner, it relates to two matters:

1. The two types of consensual division (Qismat al-Muradha’ah): A type after valuation and adjustment: If injustice (ghabn) is proven against one of the heirs in this type, they have the right to request annulment and re-division, because they took what they took believing it to be equivalent to their share of the inheritance. A type without valuation or adjustment (reconciliation): This type is treated as a sale, and the one who discovers an injustice has no right to request annulment, because they took their specific share to relinquish their full right, regardless of whether it was less or more. 2. Proximity of the claim for annulment: If a long time has passed since the division, some scholars do not consider claims of injustice, while some have set a limit of one year for this.