August 30. On this date in 1851, Bahá'u'lláh visited Karbala, where Muhammad's grandson Husayn is buried. "Imam Husayn has, as attested by the Iqan, been endowed with special grace and power among the Imams, hence the mystical reference to Bahá'u'lláh as the return of Imam Husayn, meaning the Revelation in Bahá'u'lláh of those attributes with which Imam Husayn had been specifically endowed."

August 30. On this date in 1851, Bahá'u'lláh visited Karbala, where Muhammad's grandson Husayn is buried. "Imam Husayn has, as attested by the Iqan, been endowed with special grace and power among the Imams, hence the mystical reference to Bahá'u'lláh as the return of Imam Husayn, meaning the Revelation in Bahá'u'lláh of those attributes with which Imam Husayn had been specifically endowed."

Husayn plays a key role in the Bahá'í Faith, as a letter written on behalf of Shoghi Effendi on July 30, 1941, to an individual believer affirmed:

1665. Clarification of Certain Issues Regarding Islam, the Imam Husayn, the Imamate, etc.
"Ali's appointment was clear to the Khalifs, who actually disregarded the Prophet's oral statements.
"The usurpation occurred immediately after the Prophet's death.
"Ali did not feel unqualified, but wished to avoid schism, which, unfortunately, could not be prevented.
"The schisms that have afflicted the religions preceding the Faith of Bahá'u'lláh establish its distinction from all previous Revelations, and single it out among all other Dispensations, as stated by Abdu'l-Bahá.
"The guidance vouchsafed to the Imams regarding the laws and institutions of Islam was absolute and unqualified. Their infallibility was derived directly from the Manifestation.
"The Bab's descent from the Imam Husayn is no doubt a proof of the validity of the Imamate. According to Nabil the dream the Bab had made him first conscious of His Revelation.
"The precedence of the name Husayn over Ali does establish the greatness of Imam Husayn.
"Imam Husayn has, as attested by the Iqan, been endowed with special grace and power among the Imams, hence the mystical reference to Bahá'u'lláh as the return of Imam Husayn, meaning the Revelation in Bahá'u'lláh of those attributes with which Imam Husayn had been specifically endowed.
"Joseph was one of the 'Sent Ones' of the Qur'an, meaning a Manifestation of God.
"The friends should uphold Islam as a revealed Religion in teaching the Cause but need not make, at present, any particular attempt to teach it solely and directly to non-Bahá'ís at this time.
"The mission of the American Bahá'ís is, no doubt, to eventually establish the truth of Islam in the West.
"The spirit of Islam, no doubt, was the living germ of modern Civilization; which derived its impetus from the Islamic culture in the Middle Ages, a culture that was the fruit of the Faith of Muhammad."
(From a letter written on behalf of Shoghi Effendi to an individual believer, July 30, 1941)