Ilzam here means a binding legal impact on a person, not every moral or religious obligation. It includes proof used to enforce a contested right against someone or to bar that person from an action.
Being told that a gift is offered does not have the same structure as a judicial determination that property claimed by one person actually belongs to another.
The fourth category is subtler: a principal has authority to revoke agency, yet communicating that revocation restricts the agent's future power to act. It is therefore compelling from one perspective, though the principal exercises an existing right from another.