736. As for Noah, or the member of this new Church, he was such that he believed with simplicity those things which he had come to possess from the Most Ancient Church. These were items of doctrine that had been gathered together and converted into a kind of doctrinal form by those called Enoch. The disposition of the people meant by Noah however was entirely different from those before the Flood who perished, called the Nephilim. For they immersed doctrinal matters concerning faith in their own filthy desires and in this way strove after dreadful persuasions from which they were unwilling to draw back even though they were taught by others and were shown that these were falsities. This dual genius or disposition also exists among people today. The former can be regenerated easily, but the latter with difficulty.

'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)