We have decreed, O people, that the highest and last end of all learning be the recognition of Him Who is the Object of all knowledge; and yet, behold how ye have allowed your learning to shut you out, as by a veil, from Him Who is the Dayspring of this Light, through Whom every hidden thing hath been revealed. Could ye but discover the source whence the splendour of this utterance is diffused, ye would cast away the peoples of the world and all that they possess, and would draw nigh unto this most blessed Seat of glory.

And among the people is he who layeth claim to inner knowledge
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.”