Knowledge: Milwaukee, USA
Metaphors are sometimes used in the Baha’i writings to convey intangible spiritual concepts. One metaphor that comes up in several places is the tree, such as in the Tablet of Ahmad, written by Baha’u’llah: “Verily He is the Tree of Life that bringeth forth the fruits of God, the Exalted, the Powerful, the Great.” In the quote below, knowledge is a fruit of the human tree.
Strain every nerve to acquire both inner and outer perfections, for the fruit of the human tree hath ever been and will ever be perfections both within and without. It is not desirable that a man be left without knowledge or skills, for he is then but a barren tree. Then, so much as capacity and capability allow, ye needs must deck the tree of being with fruits such as knowledge, wisdom, spiritual perception and eloquent speech.
-Baha’u’llah, The Compilation of Compilations vol. I, p. 247