During the days I lay in the prison of Tihran, though the galling weight of the chains and the stench-filled air allowed Me but little sleep, still in those infrequent moments of slumber I felt as if something flowed from the crown of My head over My breast, even as a mighty torrent that precipitateth itself upon the earth from the summit of a lofty mountain. Every limb of My body would, as a result, be set afire. At such moments My tongue recited what no man could bear to hear.

Bahá’u’lláh, Epistle to the Son of the Wolf, p. 22.

SIYAH-CHAL -- "Black Pit": the subterranean dungeon in Tihran in which Bahá’u’lláh was imprisoned August -- December 1852. Here, chained in darkness three flights of stairs underground, in the company of his fellow-Bábís and some 150 thieves and assassins, He received the first intimations of His world mission.

The Universal House of Justice, Messages 1963 to 1986, p. 751

Although most of the Bábís were taken from the prison, one by one, and martyred in the adjoining market square of Sabzih-Maydan, Bahá’u’lláh's life was providentially spared. After four months He was released but was ordered to leave Persia within a month.

Adib Taherzadeh, The Child of the Covenant, p. 58

Bahá’u’lláh spent four months in the Black Pit, during which time he contemplated the full extent of His mission. "I was but a man like others, asleep upon My couch, when lo, the breezes of the All-Glorious were wafted over Me, and taught Me the knowledge of all that hath been," He later wrote. "This thing is not from Me, but from the One Who is Almighty and All-Knowing. And he bade Me lift up My voice between earth and heaven..."

Bahá’í International Community, The Bahá’ís Magazine, 1992

Bahá’u’lláh's experience in the Black Pit set in motion a process of religious revelation which, over the next 40 years, led to the production of thousands of books, tablets and letters – which today form the core of the sacred scripture of the Bahá’í Faith. In those writings, He outlined a framework for the reconstruction of human society at all levels: spiritual, moral, economic, political, and philosophical.

Bahá’í International Community, The Bahá’ís Magazine, 1992

Because of His prominence in the defense of the Báb's cause, Bahá’u’lláh was arrested and brought, in chains and on foot, to Teheran. Protected in some measure by an impressive personal reputation and the social position of His family, as well as by protests which the Bábí pogroms had evoked from Western embassies, He was not sentenced to death, as influential figures at the royal court were urging. Instead, He was cast into the notorious Siyah-Chal, the "Black Pit", a deep, vermin-infested dungeon which had been created in one of the city's abandoned reservoirs. 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. Around Bahá’u’lláh's neck was clamped a heavy chain, so notorious in penal circles as to have been given its own name. When He did not quickly perish, as had been expected, an attempt was made to poison Him. The marks of the chain were to remain on His body for the rest of His life.

Bahá’í International Community, 1992 May 29, Statement on Bahá’u’lláh, p. 3

He was cast into the notorious "Black Pit," the Siyah-Chal in Persian. Authorities hoped this would result in His death. Instead, the dungeon became the birthplace for a new religious revelation.

Bahá’í International Community, The Bahá’ís Magazine, 1992

In the middle of the last century, one of the most notorious dungeons in the Near East was Teheran's "Black Pit." Once the underground reservoir for a public bath, its only outlet was a single passage down three steep flights of stone steps. Prisoners huddled in their own bodily wastes, languishing in the pit's inky gloom, subterranean cold and stench-ridden atmosphere. In this grim setting, the rarest and most cherished of religious events was once again played out: mortal man, outwardly human in other aspects, was summoned by God to bring to humanity a new religious revelation. The year was 1852, and the man was a Persian nobleman, known today as Bahá’u’lláh. During His imprisonment, as He sat with his feet in stocks and a 100-pound iron chain around his neck, Bahá’u’lláh received a vision of God's will for humanity. The event is comparable to those other great moments of the ancient past when God revealed Himself to His earlier Messengers: when Moses stood before the Burning Bush; when the Buddha received enlightenment under the Bodhi tree; when the Holy Spirit, in the form of a dove, descended upon Jesus; or when the Holy Spirit, in the form of a dove, descended upon Jesus; or when the archangel Gabriel appeared to Muhammad.

Bahá’í International Community, The Bahá’ís Magazine, 1992

In the Síyáh-Chál, God made known to Bahá’u’lláh His great Station. Wrapped in gloom, breathing the foulest of air, His feet in stocks, and His neck weighed down by a mighty chain, Bahá’u’lláh received the first stirrings of God’s Revelation within His soul. Under these dreadful circumstances, the “Most Great Spirit” revealed itself to Him, bidding Him to arise and speak forth the Word of God. At times, He would feel as if something flowed from the crown of His head over His breast, as a mighty torrent falls upon the earth from the summit of a high mountain. He saw the Maiden of Heaven suspended before Him, speaking to His inner and outer being, referring to Him as the Best-Beloved of the worlds, the Beauty of God, and the power of God’s sovereignty. He was assured that He would be made victorious by Himself and by His Pen, and by the aid of those whom God would raise up. Thus from behind the darkness of the Black Pit rose the Sun of Truth. The Báb’s promise had been fulfilled. The Bahá’í Revelation was born. Yet Bahá’u’lláh did not inform anyone of what had occurred. He would await the appointed hour, ordained by God, to make His Mission known.

Ruhi Book 4, p. 101-102

The Siyah-Chal was no ordinary prison but a huge underground pit which had once served as a reservoir for one of the public baths of the city. It had only one entrance. It was situated in the heart of Tihran close to a palace of the Shah and adjacent to the Sabzih-Maydan, where the Seven Martyrs of Tihran were executed. This dungeon was occupied by many prisoners, some of whom were without clothes or bedding. Its atmosphere was humid and dark, its air fetid and filled with a loathsome smell, its ground damp and littered with filth. These conditions were matched by the brutality of the guards and officials towards the Bábí victims who were chained together in that dismal place. The notorious chains of Qara-Guhar and Salasil, one of which was placed around Bahá’u’lláh's neck at all times, cut through His flesh and left their marks on His blessed body until the end of His life. They were so heavy that a special wooden fork was provided to support their weight.

Adib Taherzadeh, The Child of the Covenant, p. 56-57

Through the kindness of one of the prison officials who was friendly towards Bahá’u’lláh, His eldest son, ‘Abdu’l-Bahá, then nine years of age, was taken one day to visit His father at the Siyah-Chal. He had come only half-way down the steps when Bahá’u’lláh caught sight of Him and ordered that the child be taken out immediately. ‘Abdu’l-Bahá was permitted to wait in the prison yard until noon, when the prisoners were allowed an hour of fresh air. ‘Abdu’l-Bahá saw His father in chains and tied to His nephew, Mirza Mahmud. Bahá’u’lláh walked with great difficulty, His beard and hair were unkempt, His neck bruised and swollen from the pressure of a heavy steel collar, and His back was bent with the weight of the chain. On witnessing this sight ‘Abdu’l-Bahá fainted and was carried home, unconscious.

Adib Taherzadeh, The Child of the Covenant, p. 56

When Bahá’u’lláh came out of prison, stripped of His possessions, His back bent by the weight of the fetters, His neck swollen and injured and His health impaired, He did not intimate to anyone His experience of divine revelation. Yet those who were close to Him could not fail to witness a transformation of spirit, a power and a radiance never seen in Him before. The following is an extract from the spoken chronicle of the Greatest Holy Leaf recounting her impressions of Him at the time of His release from the Siyah-Chal: Jamai-Mubarak [lit. the Blessed Beauty, referring to Bahá’u’lláh] had a marvellous divine experience whilst in that prison. We saw a new radiance seeming to enfold him like a shining vesture, its significance we were to learn years later. At that time we were only aware of the wonder of it, without understanding, or even being told the details of the sacred event. [Quoted in Blomfield, Chosen Highway, p. 45.]

Adib Taherzadeh, The Child of the Covenant, p. 59

While breathing the foul air of the Siyah-Chal, with His feet in stocks and His head weighed down by the mighty chain, Bahá’u’lláh received, as attested by Him in His Epistle to the Son of the Wolf, the first intimations of His station as the Supreme Manifestation of God -- He whose appearance had been foretold by the Prophets of old in such terms as the 'reincarnation of Krishna', the 'fifth Buddha', the 'Shah Bahram', the 'Lord of Hosts', the Christ returned 'in the glory of the Father', the 'Spirit of God', and by the Báb as 'Him Whom God shall make manifest'.

Adib Taherzadeh, The Child of the Covenant, p. 57