Is it permissible to deduct a portion of the surplus donations for treating patients—exceeding their needs—to cover the salaries and expenses of the collection department, or the administrative and operational expenses of the charity? And is there a specific percentage for this deduction and its designated uses?

The basic principle regarding associations is that they act as agents. An agent does not act beyond the limits of what their principal has authorized. If the principal stipulates a condition, the agent must adhere to it. If the principal does not stipulate a specific condition, the agent is permitted to act in a manner dictated by what is in the best interest.

Therefore, donations for which the donor has specified a particular expenditure, such as treating the sick, may not be spent on other matters pertaining to the association.