The following quote, which teaches us about acquiring ‘spiritual eyes’ is taken from, The Revelation of Baha’u’llah, Vol. 2, p.31 by Adib Taherzadeh:
“Baha’u’llah teaches [quoting from] the Mathnavi [written by Rumi, the Sufi poet] that: ‘man will not be able to receive the Light of God in this day unless he acquires a new Eye. Eyes which are fixed on the things of this world can never see the glory of His Revelation, and ears which are tuned to the voices of the ungodly cannot hear the Melodies of the Kingdom.’ By ‘new eyes’ and ‘new ears’ He means spiritual eyes and spiritual ears. He states that since the Eye of the Spirit receives its Light from God it is shameful to let it turn to a stranger, and re-affirms that the purpose of God in creating the inner Eye was that man might behold the beauty of His Manifestation in this world.