A fresh danger now clearly threatened the life of Bahá’u’lláh. Though He Himself had stringently forbidden His followers, on several occasions, both verbally and in writing, any retaliatory acts against their tormentors, and had even sent back to Beirut an irresponsible Arab convert, who had meditated avenging the wrongs suffered by his beloved Leader, seven of the companions clandestinely sought out and slew three of their persecutors, among whom were Siyyid Muḥammad and Áqá Ján.
The consternation that seized an already oppressed community was indescribable. Bahá’u’lláh’s indignation knew no bounds. "Were We", He thus voices His emotions, in a Tablet revealed shortly after this act had been committed, "to make mention of what befell Us, the heavens would be rent asunder and the mountains would crumble." "My captivity", He wrote on another occasion, "cannot harm Me. That which can harm Me is the conduct of those who love Me, who claim to be related to Me, and yet perpetrate what causeth My heart and My pen to groan."
193. Select ye a single language ... adopt ye ... a common script. [#189]
Bahá’u’lláh enjoins the adoption of a universal language and script. His Writings envisage two stages in this process. The first stage is to consist of the selection of an existing language or an invented one which would then be taught in all the schools of the world as an auxiliary to the mother tongues. The governments of the world through their parliaments are called upon to effect this momentous enactment. The second stage, in the distant future, would be the eventual adoption of one single language and common script for all on earth.
194. We have appointed two signs for the coming of age of the human race [#189]
The first sign of the coming of age of humanity referred to in the Writings of Bahá’u’lláh is the emergence of a science which is described as that "divine philosophy" which will include the discovery of a radical approach to the transmutation of elements. This is an indication of the splendours of the future stupendous expansion of knowledge.
Concerning the "second" sign which Bahá’u’lláh indicates to have been revealed in the Kitáb-i-Aqdas, Shoghi Effendi states that Bahá’u’lláh, "...in His Most Holy Book, has enjoined the selection of a single language and the adoption of a common script for all on earth to use, an injunction which, when carried out, would, as He Himself affirms in that Book, be one of the signs of the ‘coming of age of the human race’".
Further insight into this process of mankind’s coming of age and proceeding to maturity is provided by the following statement of Bahá’u’lláh: