This summary is not the rule. The rule text controls.
When someone dies and their estate goes through the court process, the heirs and people named in the will usually cannot ask the court to divide up the property right away. They have to wait until they are legally allowed to take possession of the property under certain specific rules.
In practical terms, this means the estate has to reach a certain point in the legal process before anyone can request that the property be split among the heirs. The court needs to first confirm who is entitled to receive the property and clear them to take possession of it. Only after that happens can any of the heirs or legatees file a request to partition, or divide, the succession property.
This rule exists to keep things in order. It stops people from rushing to divide up property before the estate has been properly settled and before it is clear who actually has the right to receive it.