Within thirty days after the service of any ruling, Order or decision of the Division based upon a hearing, any party or person affected thereby may apply for a rehearing thereof in respect of any matter connected therewith specified in such application for rehearing. Petitions for rehearing shall be in writing, and shall state specifically the grounds relied upon for such rehearing, and shall be accompanied by proof of service thereof upon all the parties and persons affected thereby.
Ill. Admin. Code tit. 92, § 14.1195