Universal House of Justice "cannot legislate to make possible the appointment of a successor to Shoghi Effendi", nor "the appointment of any more Hands of the Cause"

As the Universal House of Justice has already announced, it cannot legislate to make possible the appointment of a successor to Shoghi Effendi, nor can it legislate to make possible the appointment of any more Hands of the Cause, but it must do everything within its power to ensure the performance of all those functions which it shares with these two mighty Institutions. It must make provision for the proper discharge in future of the functions of protection and propagation, which the administrative bodies share with the Guardianship and the Hands of the Cause; it must, in the absence of the Guardian, receive and disburse the Huqúqu’lláh, in accordance with the following statement of ‘Abdu’l Bahá: “Disposition of the Huqúq, wholly or partly, is permissible, but this should be done by permission of the authority in the Cause to whom all must turn”; it must make provision in its Constitution for the removal of any of its members who commits a sin “injurious to the common weal.” Above all, it must, with perfect faith in Bahá’u’lláh, proclaim His Cause and enforce His Law so that the Most Great Peace shall be firmly established in this world and the foundation of the Kingdom of God on earth shall be accomplished. 

- The Universal House of Justice  (From a message dated 27 May 1966 to an individual believer; Online Baha’i Reference Library of the Baha’i World Center)