October 20

…the Báb’s holy dust. So precious is this dust that the very earth surrounding the edifice enshrining this dust has been extolled by the Center of Bahá’u’lláh’s Covenant, in one of His Tablets in which He named the five doors belonging to the six chambers which He originally erected after five of the believers associated with the construction of the Shrine, as being endowed with such potency as to have inspired Him in bestowing these names, whilst the tomb itself housing this dust He acclaimed as the spot round which the Concourse on high circle in adoration. 
(Shoghi Effendi, from a letter dated March 29, 1951; ‘Citadel of Faith’)