Hidden Words, also known as Book of Fatimih (Kalimát-i-Maknúnih):
published in Lights of Guidance
...Bahá'u'lláh says in Hidden Words; 'Breathe not the sins of others so long as thou art a sinner. Shouldst thou transgress this command ACCURSED ARE THOU.' The condemnation of backbiting could hardly be couched in stronger language than in these passages, and it is obviously one of the foremost obligations for Bahá'ís to set their faces against this practice. Even if what is said against another person be true, the mentioning of his faults to others still comes under the category of backbiting, and is forbidden."
(From a letter written on behalf of Shoghi Effendi to the National Spiritual Assembly of the British Isles, February 11, 1925)
#596. Regarding Covenant entered into on Mount Paran
"As for the reference in the Hidden Words regarding the Covenant entered into on Mount Paran, this signifieth that in the sight of God the past, the present and the future are all one and the same whereas, relative to man, the past is gone and forgotten, the present is fleeting, and the future is within the realm of hope. And it is a basic principle of the Law of God that in every Prophetic Mission, He entereth into a Covenant with all believers - - a Covenant that endureth until the end of that Mission, until the promised day when the Personage stipulated at the outset of the Mission is made manifest. Consider Moses, He Who conversed with God. Verily, upon Mount Sinai, Moses entered into a Covenant regarding the Messiah, with all those souls who would live in the day of the Messiah. And those souls, although they appeared many centuries after Moses, were nevertheless — so far as the Covenant, which is outside time, was concerned — present there with Moses. The Jews, however, were heedless of this and remembered it not, and thus they suffered a great and clear loss."
('Abdu'l-Bahá: Selections from the Writings of 'Abdu'l-Bahá, p. 207)
#600. Speaking Against the Covenant
"My purpose is to explain to you that it is your duty to guard the religion of God so that none shall be able to assail it outwardly or inwardly. If you find harmful teachings are being set forth by some individual no matter who that individual be, even though he should be My own son, know verily that I am completely severed from him. If anyone speaks against the Covenant, even though he should be My son, know that I am opposed to him. Those who speak falsehoods, who covet worldly things and seek to accumulate the riches of this earth are not of Me. But when you find a person living up to the Teachings of Bahá'u'lláh, following the percepts of the Hidden Words, know that he belongs to Bahá'u'lláh and verily I proclaim that he is of Me...."
('Abdu'l-Bahá: The Promulgation of Universal Peace, p. 456-457)
#1601. Hidden Words
"As regards to the passage No. 13 of the Arabic Hidden Words: that which Bahá'u'lláh declares we can find abiding within us is the power of the Divine Spirit, however, can in no way be compared to the Revelation which God discloses to His Prophets and Messengers. The similarity in the terminology should not confuse this distinction which is most fundamental."
(From a letter written on behalf of Shoghi Effendi to two believers, December 7, 1935)
#1631. The Title 'Hidden Words' was Given by Bahá'u'lláh
"... The title 'Hidden Words' was given by Bahá'u'lláh because there is a tradition in Islam, that Fatimih, Muhammad's daughter, grieved greatly over the Martyrdom of her son, and God sent Gabriel to speak encouraging words to her. These words were 'hidden', only she having heard them, and in these latter days the Promised One has revealed them, thus fulfilling a tradition."
(From a letter written on behalf of Shoghi Effendi to an individual believer, December 20, 1949)
#1632. The Meaning of the Name 'Hidden Words'
"With regard to your question concerning the meaning of the name 'Hidden Words'. It is, indeed, one of the most suggestive titles of the Writings of Bahá'u'lláh. These words are called hidden due to the fact that men have had neither the knowledge nor a true sense of appreciation of them before they were revealed by Bahá'u'lláh. It is through Him, Who is the sole Mouthpiece of God in this age, that spiritual realities and truths have been once more reinterpreted and revealed afresh to mankind. Bahá'u'lláh's Message is thus the only key to a true revealed afresh to mankind. Bahá'u'lláh's Message is thus the only key to a true understanding of the mysteries that envelop man's spiritual life."
(From a letter written on behalf of Shoghi Effendi to an individual believer, September 1, 1935)
#1633. The Hidden Words Have no Sequence
"The Hidden Words have no sequence. They are jewel-like thoughts cast out of the mind of the Manifestation of God to admonish and counsel men..."
(From a letter written on behalf of Shoghi Effendi to an individual believer, October 22, 1949)
#1634. Passages in Which Bahá'u'lláh Refers to Man as "Son of Spirit"
"As to your second question concerning those passages in the 'Hidden Words' in which Bahá'u'lláh refers to man as 'Son of Spirit', 'Son of existence', 'Son of humanity' etc., the word son used in this connection is a kind of collective noun, meaning mankind and has, therefore, no connotation of any sex differentiation between man and woman whatever."
(From a letter written on behalf of Shoghi Effendi to an individual believer, January 19, 1935)
#1635. Hidden Words (Arabic) No. 13 Explained
"Thou hast asked about the statement in the Hidden Words which reads, 'O Son of Spirit! Turn thy face so that thou mayest find Me within thee, Powerful Mighty, and Supreme.' This is the statement to which His Holiness, the Christ, referred His Apostles in the Gospel, saying: 'The Father is in the Son and the Son is in you.'
"This is evident that, when the hearts are purified and through the divine education and heavenly teachings become the manifestators of infinite perfections, they are like clear mirrors and the Sun of Truth will reflect with might, power and omnipotence in such mirrors, and to such an extent that whatsoever is brought before them is illumined and ignited. This is a brief interpretation because of lack of time. Therefore, do thou reflect and ponder over it, so that the doors of significance may be opened before thine eyes."
('Abdu'l-Bahá: Extract from Tablet to Thornton Chase, June 1911: Star of the West Vol. II, Nos. 7 and 8, pp. 11-12)