Eventually, still without trial or recourse, Bahá’u’lláh was released from prison and immediately banished from His native land, His wealth and properties arbitrarily confiscated. The Russian diplomatic representative, who knew Him personally and who had followed the Bábí persecutions with growing distress, offered Him his protection and refuge in lands under the control of his government. In the prevailing political climate, acceptance of such help would almost certainly have been misrepresented by others as having political implications. Perhaps for this reason, Bahá’u’lláh chose to accept banishment to the neighboring territory of Iraq, then under the rule of the Ottoman Empire. This expulsion was the beginning of forty years of exile, imprisonment, and bitter persecution.
He followed the path that had been taken by all of the Messengers of God gone before Him, and withdrew to the wilderness, choosing for the purpose the mountain region of Kurdistan. His withdrawal, as He later said, had “contemplated no return.” Its reason “was to avoid becoming a subject of discord among the faithful, a source of disturbance unto Our companions.” Although the two years spent in Kurdistan were a period of intense privation and physical hardship, Bahá’u’lláh describes them as a time of profound happiness during which He reflected deeply on the message entrusted to Him: “Alone, We communed with Our spirit, oblivious of the world and all that is therein.”Only with great reluctance, believing it His responsibility to the cause of the Báb, did He eventually accede to urgent messages from the remnant of the desperate group of exiles in Baghdad who had discovered His whereabouts and appealed to Him to return and assume the leadership of their community.
Two of the most important volumes of Bahá’u’lláh’s writings date from this first period of exile, preceding the declaration of His mission in 1863. The first of these is a small book which He named The Hidden Words. Written in the form of a compilation of moral aphorisms, the volume represents the ethical heart of Bahá’u’lláh’s message. 
In verses which Bahá’u’lláh describes as a distillation of the spiritual guidance of all the Revelations of the past, the voice of God speaks directly to the human soul:
“O Son of Spirit! The best beloved of all things in My sight is Justice; turn not away therefrom if thou desirest Me, and neglect it not that I may confide in thee. By its aid thou shalt see with thine own eyes and not through the eyes of others, and shalt know of thine own knowledge and not through the knowledge of thy neighbor. Ponder this in thy heart; how it behooveth thee to be. Verily justice is My gift to thee and the sign of My loving-kindness. Set it then before thine eyes. “
“O Son of Being! Love Me that I may love thee. If thou lovest Me not, My love can in no wise reach thee. Know this, O servant. “
O Son of Man! Sorrow not save that thou art far from Us. Rejoice not save that thou art drawing near and returning unto Us.…
“O Son of Being! With the hands of power I made thee and with the fingers of strength I created thee; and within thee have I placed the essence of My light. Be thou content with it and seek naught else, for My work is perfect and My command is binding. Question it not, nor have a doubt thereof.”
The second of the two major works composed by Bahá’u’lláh during this period is The Book of Certitude, 
a comprehensive exposition of the nature and purpose of religion. In passages that draw not only on the Qur’án, but with equal facility and insight on the Old and New Testaments, the Messengers of God are depicted as agents of a single, unbroken process, the awakening of the human race to its spiritual and moral potentialities. A humanity which has come of age can respond to a directness of teaching that goes beyond the language of parable and allegory; faith is a matter not of blind belief, but of conscious knowledge. Nor is the guidance of an ecclesiastical elite any longer required: the gift of reason confers on each individual in this new age of enlightenment and education the capacity to respond to Divine guidance. The test is that of sincerity:
“No man shall attain the shores of the ocean of true understanding except he be detached from all that is in heaven and on earth.… The essence of these words is this: they that tread the path of faith, they that thirst for the wine of certitude, must cleanse themselves of all that is earthly—their ears from idle talk, their minds from vain imaginings, their hearts from worldly affections, their eyes from that which perisheth. They should put their trust in God, and, holding fast unto Him, follow in His way. Then will they be made worthy of the effulgent glories of the sun of divine knowledge and understanding, … inasmuch as man can never hope to attain unto the knowledge of the All-Glorious … unless and until he ceases to regard the words and deeds of mortal men as a standard for the true understanding and recognition of God and His Prophets. Consider the past. How many, both high and low, have, at all times, yearningly awaited the advent of the Manifestations of God in the sanctified persons of His chosen Ones.… And whensoever the portals of grace did open, and the clouds of divine bounty did rain upon mankind, and the light of the Unseen did shine above the horizon of celestial might, they all denied Him, and turned away from His face—the face of God Himself.… Only when the lamp of search, of earnest striving, of longing desire, of passionate devotion, of fervid love, of rapture, and ecstasy, is kindled within the seeker’s heart, and the breeze of His lovingkindness is wafted upon his soul, will the darkness of error be dispelled, the mists of doubts and misgivings be dissipated, and the lights of knowledge and certitude envelop his being.… Then will the manifold favors and outpouring grace of the holy and everlasting Spirit confer such new life upon the seeker that he will find himself endowed with a new eye, a new ear, a new heart, and a new mind.… Gazing with the eye of God, he will perceive within every atom a door that leadeth him to the stations of absolute certitude. He will discover in all things the … evidences of an everlasting Manifestation. …When the channel of the human soul is cleansed of all worldly and impeding attachments, it will unfailingly perceive the breath of the Beloved across immeasurable distances, and will, led by its perfume, attain and enter the City of Certitude.… …That city is none other than the Word of God revealed in every age and dispensation.… All the guidance, the blessings, the learning, the understanding, the faith, and certitude, conferred upon all that is in heaven and on earth, are hidden and treasured within these Cities”
Though living in very straitened material circumstances, the exiles were galvanized by this vision. One of their company, a man called Nabíl, who was later to leave a detailed history of both the ministries of the Báb and Bahá’u’lláh, has described the spiritual intensity of those days:Many a night no less than ten persons subsisted on no more than a pennyworth of dates. No one knew to whom actually belonged the shoes, the cloaks, or the robes that were to be found in their houses. Whoever went to the bazaar could claim that the shoes upon his feet were his own, and each one who entered the presence of Bahá’u’lláh could affirm that the cloak and robe he then wore belonged to him.… O, for the joy of those days, and the gladness and wonder of those hours!
To the dismay of the Persian consular authorities who had believed the Bábí “episode” to have run its course, the community of exiles gradually became a respected and influential element in Iraq’s provincial capital and the neighboring towns.
(Ref: part of statement prepared by the Bahá’í International Community Office of Public Information)
No charges were laid but He and some thirty companions were, without appeal, kept immured in the darkness and filth of this pit, surrounded by hardened criminals, many of them under sentence of death.
