The short duration of His [Báb's] Dispensation, the restricted range within which His laws and ordinances have been made to operate, supply no criterion whatever wherewith to judge its Divine origin and to evaluate the potency of its message. “That so brief a span,” Bahá’u’lláh Himself explains, “should have separated this most mighty and wondrous Revelation from Mine own previous Manifestation, is a secret that no man can unravel and a mystery such as no mind can fathom. Its duration had been foreordained, and no man shall ever discover its reason unless and until he be informed of the contents of My Hidden Book.”
- Shoghi Effendi (‘The Dispensation of Baha’u’llah; included in ‘The World Order of Baha’u’llah’)