This is a reference to people who claim access to esoteric knowledge and whose attachment to such knowledge veils them from the Revelation of the Manifestation of God. Elsewhere Bahá’u’lláh affirms: "They that are the worshippers of the idol which their imaginations have carved, and who call it Inner Reality, such men are in truth accounted among the heathen."
61. How many a man hath secluded himself in the climes of India, denied himself the things that God hath decreed as lawful, imposed upon himself austerities and mortifications [#36]
These verses constitute the prohibition of monasticism and asceticism. See the Synopsis and Codification, section IV.D. 1.y.iii.-iv. In the Words of Paradise Bahá’u’lláh amplifies these provisions. He states: "Living in seclusion or practising asceticism is not acceptable in the presence of God," and He calls upon those involved to "observe that which will cause joy and radiance". He instructs those who have taken up "their abodes in the caves of the mountains" or who have "repaired to graveyards at night" to abandon these practices, and He enjoins them not to deprive themselves of the "bounties" of this world which have been created by God for humankind. And in the Tablet of Bis̱ẖárát, while acknowledging the "pious deeds" of monks and priests, Bahá’u’lláh calls upon them to "give up the life of seclusion and direct their steps towards the open world and busy themselves with that which will profit themselves and others". He also grants them leave "to enter into wedlock that they may bring forth one who will make mention of God".
62. Whoso layeth claim to a Revelation direct from God, ere the expiration of a full thousand years [#37]
The Dispensation of Bahá’u’lláh will last until the coming of the next Manifestation of God, Whose advent will not take place before at least "a full thousand years" will have elapsed. Bahá’u’lláh cautions against ascribing to "this verse" anything other than its "obvious meaning", and in one of His Tablets, He specifies that "each year" of this thousand year period consists of "twelve months according to the Qur’án, and of nineteen months of nineteen days each, according to the Bayán".
The intimation of His Revelation to Bahá’u’lláh in the Síyáh-C̱ẖál of Ṭihrán, in October 1852, marks the birth of His Prophetic Mission and hence the commencement of the one thousand years or more that must elapse before the appearance of the next Manifestation of God.