"Give ear unto God’s holy Voice, and heed thou His sweet and immortal melody."

"Give ear unto God’s holy Voice, and heed thou His sweet and immortal melody. Behold how He hath solemnly warned them that have repudiated the verses of God, and hath disowned them that have denied His holy words. Consider how far the people have strayed from the Kawthar of the divine Presence, and how grievous hath been the faithlessness and arrogance of the spiritually destitute in the face of that sanctified Beauty. Although that Essence of lovingkindness and bounty caused those evanescent beings to step into the realm of immortality, and guided those destitute souls to the sacred river of wealth, yet some denounced Him as “a calumniator of God, the Lord of all creatures,” others accused Him of being “the one that withholdeth the people from the path of faith and true belief,” and still others declared Him to be “a lunatic” and the like."

-Bahá'u'lláh, The Kitáb-i-Íqán , p. 215

" ... know of a certainty that the people in every age, clinging to a verse of the Book, have uttered such vain and absurd sayings, contending that no Prophet should again be made manifest to the world."

"Therefore, understand from this verse and know of a certainty that the people in every age, clinging to a verse of the Book, have uttered such vain and absurd sayings, contending that no Prophet should again be made manifest to the world. Even as the Christian divines who, holding fast to the verse of the Gospel to which We have already referred, have sought to explain that the law of the Gospel shall at no time be annulled, and that no independent Prophet shall again be made manifest, unless He confirmeth the law of the Gospel. Most of the people have become afflicted with the same spiritual disease." ...

-Bahá'u'lláh, The Kitáb-i-Íqán , p.213

“None knoweth the interpretation thereof but God and they that are well-grounded in knowledge.”

"Even as thou dost witness how the people of the Qur’án, like unto the people of old, have allowed the words “Seal of the Prophets” to veil their eyes. And yet, they themselves testify to this verse: “None knoweth the interpretation thereof but God and they that are well-grounded in knowledge.” 13 And when He Who is well-grounded in all knowledge, He Who is the Mother, the Soul, the Secret, and the Essence thereof, revealeth that which is the least contrary to their desire, they bitterly oppose Him and shamelessly deny Him. These thou hast already heard and witnessed. Such deeds and words have been solely instigated by leaders of religion, they that worship no God but their own desire, who bear allegiance to naught but gold, who are wrapt in the densest veils of learning, and who, enmeshed by its obscurities, are lost in the wilds of error. Even as the Lord of being hath explicitly declared: “What thinkest thou? He who hath made a God of his passions, and whom God causeth to err through a knowledge, and whose ears and whose heart He hath sealed up, and over whose sight He hath cast a veil—who, after his rejection by God, shall guide such a one? Will ye not then be warned?” 14"

-Bahá'u'lláh, The Kitáb-i-Íqán , pp. 213-214

13. Qur’án 3:7 
14. Qur’án 45:22

“In a rich soil, its plants spring forth abundantly by permission of its Lord, and in that soil which is bad, they spring forth but scantily.”

"O my brother! A divine Mine only can yield the gems of divine knowledge, and the fragrance of the mystic Flower can be inhaled only in the ideal Garden, and the lilies of ancient wisdom can blossom nowhere except in the city of a stainless heart. “In a rich soil, its plants spring forth abundantly by permission of its Lord, and in that soil which is bad, they spring forth but scantily.” 31"

-Bahá'u'lláh, The Kitáb-i-Íqán, p. 191


31. Qur’án 7:57.

"He will contemplate the manifest signs of the universe, and will penetrate the hidden mysteries of the soul."

"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 loving-kindness 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. At that hour will the mystic Herald, bearing the joyful tidings of the Spirit, shine forth from the City of God resplendent as the morn, and, through the trumpet-blast of knowledge, will awaken the heart, the soul, and the spirit from the slumber of negligence. Then will the manifold favours 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. He will contemplate the manifest signs of the universe, and will penetrate the hidden mysteries of the soul. 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 mysteries of divine Revelation and the evidences of an everlasting manifestation."

-Bahá'u'lláh, The Kitáb-i-Íqán , pp. 195-196

“The most grievous of all veils is the veil of knowledge.”

"In this day, they that are submerged beneath the ocean of ancient Knowledge, and dwell within the ark of divine wisdom, forbid the people such idle pursuits. Their shining breasts are, praise be to God, sanctified from every trace of such learning, and are exalted above such grievous veils. We have consumed this densest of all veils, with the fire of the love of the Beloved—the veil referred to in the saying: “The most grievous of all veils is the veil of knowledge.” Upon its ashes, We have reared the tabernacle of divine knowledge. We have, praise be to God, burned the “veils of glory” with the fire of the beauty of the Best-Beloved. We have driven from the human heart all else but Him Who is the Desire of the world, and glory therein. We cleave to no knowledge but His Knowledge, and set our hearts on naught save the effulgent glories of His light."

-Bahá'u'lláh, The Kitáb-i-Íqán, pp. 187-188

“In truth, they who plighted fealty unto thee, really plighted that fealty unto God.”

"Were any of the all-embracing Manifestations of God to declare: “I am God!” He verily speaketh the truth, and no doubt attacheth thereto. For it hath been repeatedly demonstrated that through their Revelation, their attributes and names, the Revelation of God, His name and His attributes, are made manifest in the world. Thus, He hath revealed: “Those shafts were God’s, not Thine!” 18 And also He saith: “In truth, they who plighted fealty unto thee, really plighted that fealty unto God.” 19 And were any of them to voice the utterance: “I am the Messenger of God,” He also speaketh the truth, the indubitable truth. Even as He saith: “Muḥammad is not the father of any man among you, but He is the Messenger of God.” 20 Viewed in this light, they are all but Messengers of that ideal King, that unchangeable Essence. And were they all to proclaim: “I am the Seal of the Prophets,” they verily utter but the truth, beyond the faintest shadow of doubt. For they are all but one person, one soul, one spirit, one being, one revelation. They are all the manifestation of the “Beginning” and the “End,” the “First” and the “Last,” the “Seen” and “Hidden”—all of which pertain to Him Who is the innermost Spirit of Spirits and eternal Essence of Essences. And were they to say: “We are the servants of God,” this also is a manifest and indisputable fact."  ...

-Bahá'u'lláh, The Kitáb-i-Íqán ,pp. 178-179

 18. Qur’án 8:17. 
 19. Qur’án 48:10. 
 20. Qur’án 33:40.