Selection from Arcana Coelestia ~ Emanuel Swedenborg
In Mark 4:26-29, the comparison with the blade, the ear*, and the corn, involves the rebirth of man by means of memory-knowledges, truths of faith, and goods of charity:Jesus said, So is the kingdom of God, as when a man casteth seed upon the earth; then sleepeth and riseth night and day, but the seed germinates and grows while he knoweth not. For the earth beareth fruit of itself; first the blade, then the ear, after that the corn in the ear. But when the fruit is brought forth, immediately he putteth in the sickle, because the harvest is come (Mark 4:26-29);the "kingdom of God," which is compared to the blade, the ear, and the corn, is heaven in man through regeneration; for one who has been regenerated has the kingdom of God within him, and becomes in image the kingdom of God or heaven. The "blade" is the first memory-knowledge; the "ear" is the memory-knowledge of truth thence derived; the "corn" is the derivative good.
Moreover, the laws enacted in regard to gleanings (Lev. 19:9; 23:22), and in regard to the liberty of plucking the ears from the standing corn of the neighbor (Deut. 23:25), and also in regard to eating no bread, nor parched corn, nor green ears, until the offering of God was brought (Lev. 23:14), represented such things as are signified by "ears."
***
* The reason why "ears" or spikes of corn signify memory-knowledges, is that "corn" signifies the good of the natural, because memory-knowledges are the containants of the good of the natural, as the ears are of the corn; for in general all truths are vessels of good, and so also are memory-knowledges, for these are lowest truths.
Lowest truths, or truths of the exterior natural, are called memory-knowledges, because they are in man's natural or external memory, and because they partake for the most part of the light of the world, and hence can be presented and represented to others by forms of words, or by ideas formed into words by means of such things as are of the world and its light.
The things in the inner memory, however, insofar as they partake of the light of heaven, are not called memory-knowledges, but truths; nor can they be understood except by means of this light, or expressed except by forms of words, or ideas formed into words, by means of such things as are of heaven and its light.
***
The memory-knowledges into which the things of faith and of charity can be applied are very many, such as all the memory-knowledges of the church which are signified by "Egypt" in a good sense; and consequently all those memory-knowledges which are truths about correspondences, representatives, significatives, influx, order, intelligence and wisdom, and the affections; and also all truths of inner and outer nature, both visible and invisible, because these correspond to spiritual truths.
(from Arcana Coelestia 5212 - 5214)