Such decree may be rendered by the presiding chancellor of the court in vacation at any time or place within his district, provided summons has been served on the heirs of the decedent, or devisees under the will of the testator, in the manner provided by law for the service of summons on defendants in chancery for at least ten days before the hearing. In such summons, the time and place of the hearing and the purpose of the proceeding shall be definitely stated; and should the summons be published, such publication shall be completed at least ten days before the hearing.