The abjad numerical equivalent of "Bahá" is nine. The Universal House of Justice and the National and Local Spiritual Assemblies currently have nine members each, the minimum number prescribed by Bahá’u’lláh.
51. It behoveth them to be the trusted ones of the Merciful among men [#30]
The general powers and duties of the Universal House of Justice, the National Spiritual Assemblies and the Local Spiritual Assemblies and the qualifications for membership are set forth in the Writings of Bahá’u’lláh and ‘Abdu’l-Bahá, in the letters of Shoghi Effendi, and in the elucidations of the Universal House of Justice. The major functions of these institutions are outlined in the Constitution of the Universal House of Justice, and in those of the National and Local Spiritual Assemblies.
52. take counsel together [#30]
Bahá’u’lláh has established consultation as one of the fundamental principles of His Faith and has exhorted the believers to "take counsel together in all matters". He describes consultation as "the lamp of guidance which leadeth the way" and as "the bestower of understanding". Shoghi Effendi states that the "principle of consultation ... constitutes one of the basic laws" of the Bahá’í Administrative Order.
In Questions and Answers, number 99, Bahá’u’lláh outlines an approach to consultation and stresses the importance of achieving unanimity in decision-making, failing which the majority decision must prevail. The Universal House of Justice has clarified that this guidance concerning consultation was revealed before Spiritual Assemblies had been established and was in answer to a question about the Bahá’í teachings on consultation. The House of Justice affirms that the emergence of Spiritual Assemblies, to which the friends may always turn for assistance, in no way prohibits them from following the procedure outlined in Questions and Answers. This approach may be used by the friends, should they wish, when they desire to consult on their personal problems.