And again, another parable put [the Savior] forth unto them, having an allusion to the kingdom which should be set up, just previous or at the time of the harvest, which reads as follows: “The kingdom of heaven is like to a grain of mustard seed, which a man took and sowed in his field, which indeed is the least of all seeds, but when it is grown it is the greatest among herbs, and becometh a tree, so that the birds of the air come and lodge in the branches thereof” [Mt 13.31–32]. Now we can discover plainly, that this figure is given to represent the Church as it shall come forth in the last days. Behold, the kingdom of heaven is likened unto it. Now, what is like unto it?
Let us take the Book of Mormon, which a man took and hid in his field; securing it by his faith, to spring up in the last days, or in due time: let us behold it coming forth out of the ground, which is indeed accounted the least of all seeds, but behold it branching forth; yea, even towering, with lofty branches, and God-like majesty, until it [like the mustard seed] becomes the greatest of all herbs: and it is truth, and it has sprouted and come forth out of the earth; and righteousness begins to look down from heaven [Ps 85.11]; and God is sending down His powers, gifts and angels, to lodge in the branches thereof.