'Grass' is natural truth, and 'flower of the field' is spiritual truth, as in Isaiah 40:5, 6. Green grass, in the Word, signifies the good and truth of the church, and of faith, which first springs up in the natural man. This is also signified by 'herb in the field.' Grass and the pulse of the herb, as in Psalm 32:2, signify what is most vile. Grass signifies science from a spiritual origin, or that by which spiritual truth is confirmed. 'Reeds and rushes' signify science from a sensory origin, or the things which confirm the fallacies of the senses, as in Isaiah 25:7. This science, considered in itself, is only a part of the lowest natural degree, which may be justly called material and bodily, in which there is little or no life. Green grass also signifies that which is alive with man. 'Grass burnt up' signifies the things which are dead in him. Grass signifies the scientific principle. Just as green grass serves animals for support, spiritual truth serves men for spiritual nourishment.

(References: Apocalypse Explained 507)

116. THE SUN IN HEAVEN.

In heaven neither the sun of the world, nor anything from that sun, is seen, because it is wholly natural. For nature has its beginning from that sun, and whatever is produced by means of it is called natural. But the spiritual, to which heaven belongs, is above nature and wholly distinct from what is natural; and there is no communication between the two except by correspondences. What the distinction between them is may be understood from what has been already said about degrees (38), and what the communication is from what has been said in the two preceding chapters about correspondences.