"Hearken with thine inner ear unto the Voice of Jeremiah, Who saith: “Oh, for great is that Day, and it hath no equal.”

"O Shaykh! Hearken unto the melodies of the Gospel with the ear of fairness. He saith—glorified be His utterance—prophesying the things that are to come: “But of that Day and Hour knoweth no man, no, not the angels of heaven, nor the Son, but the Father.” By Father in this connection is meant God—exalted be His glory. He, verily, is the True Educator, and the Spiritual Teacher.

Joel saith: “For the Day of the Lord is great and very terrible; and who can abide it?” Firstly, in the sublime utterance set forth in the Gospel He saith that none is aware of the time of the Revelation, that none knoweth it except God, the All-Knowing, Who is cognizant of all. Secondly, He setteth forth the greatness of the Revelation. Likewise, in the Qur’án He saith: “Of what ask they of one another? Of the Great Announcement.” This is the Announcement, the greatness of which hath been mentioned in most of the Books of old and of more recent times. This is the Announcement that hath caused the limbs of mankind to quake, except such as God, the Protector, the Helper, the Succorer, hath willed to exempt. Men have indeed with their own eyes witnessed how all men and all things have been thrown into confusion and been sore perplexed, save those whom God hath chosen to exempt.

O Shaykh! Great is the Cause, and great the Announcement! Patiently and calmly ponder thou upon the resplendent signs and the sublime words, and all that hath been revealed in these days, that haply thou mayest fathom the mysteries that are hid in the Books, and mayest strive to guide His servants. Hearken with thine inner ear unto the Voice of Jeremiah, Who saith: “Oh, for great is that Day, and it hath no equal.” Wert thou to observe with the eye of fairness, thou wouldst perceive the greatness of the Day. Incline thine ear unto the Voice of this All-Knowing Counsellor, and suffer not thyself to be deprived of the mercy that hath surpassed all created things, visible and invisible. Lend an ear unto the song of David. He saith: “Who will bring me into the Strong City?” The Strong City is ‘Akká, which hath been named the Most Great Prison, and which possesseth a fortress and mighty ramparts."

-Bahá'u'lláh, Epistle to the Son of the Wolf, pp. 143-144

Jeremiah by Michaelangelo