The “hostility, the flagrant injustice, the iniquity and rebellion of Mírzá Yahyá”

And still another of His [Baha'u'llah's] trials was the hostility, the flagrant injustice, the iniquity and rebellion of Mírzá Yahyá. Although that Wronged One, that Prisoner, had through His loving-kindness nurtured him in His own bosom ever since his early years, had showered at every moment His tender care upon him, exalted his name, shielded him from every misfortune, endeared him to them of this world and the next, and despite the firm exhortations and counsels of His Holiness, the Exalted One (the Báb) and His clear and conclusive warning;—”Beware, beware, lest the Nineteen Letters of the Living and that which hath been revealed in the Bayán veil thee!” yet notwithstanding this, Mírzá Yahyá denied Him, dealt falsely with Him, believed Him not, sowed the seeds of doubt, closed his eyes to His manifest verses and turned aside therefrom. Would that he had been content therewith! Nay, he even attempted to shed the sacred blood (of Bahá’u’lláh) and then raised a great clamor and tumult around him, attributing unto Bahá’u’lláh malevolence and cruelty towards himself. What sedition he stirred up and what a storm of mischief he raised whilst in the Land of Mystery (Adrianople)! At last, he wrought that which caused the Day-Star of the world to be sent an exile to this, the Most Great Prison, and sorely wronged, and in the West of this Great Prison He did set. 

- ‘Abdu’l-Baha  (‘The Will and Testament of ‘Abdu’l-Baha)