Bahá’u’lláh says: “Know thou that upon Our arrival at this Spot, We chose to designate it as the ‘Most Great Prison’. Though previously subjected in another land (Tihrán) to chains and fetters, We yet refused to call it by that name. Say: Ponder thereon, O ye endued with understanding!” To the unimaginable sufferings Bahá’u’lláh was made to bear in that grim place was added an indescribable loss: while pacing the roof of the barracks, rapt in his customary devotions one evening, ‘Abdu’l-Bahá’s beloved younger brother Mirzá Mihdí, 22, fell through an open skylight onto a wooden crate, which pierced his body and caused him to expire twenty-two hours later.