Moreover, the comparison "as small as a mustard seed" was in every-day use among Jews of the time. The comparison employed by Jesus on another occasion evidences the common usage, as when He said: "If ye have faith as a grain of mustard seed ... nothing shall be impossible unto you."[631] It should be known that the mustard plant attains in Palestine a larger growth than in more northerly climes.[632] The lesson of the parable is easy to read. The seed is a living entity. When rightly planted it absorbs and assimilates the nutritive matters of soil and atmosphere, grows, and in time is capable of affording lodgment and food to the birds. So the seed of truth is vital, living, and capable of such development as to furnish spiritual food and shelter to all who come seeking. In both conceptions, the plant at maturity produces seed in abundance, and so from a single grain a whole field may be covered. THE LEAVEN. "Another parable spake he unto them; The kingdom of heaven is like unto leaven, which a woman took, and hid in three measures of meal, till the whole was leavened."[633] Points of both similarity and contrast between this parable and the last are easily discerned. In each the inherent vitality and capacity for development, so essentially characteristic of the kingdom of God, are illustrated. The mustard seed however, typifies the effect of vital growth in gathering the substance of value from without; while the leaven or yeast disseminates and diffuses outward its influence throughout the mass of otherwise dense and sodden dough. Each of these processes represents a means whereby the Spirit of Truth is made effective. Yeast is no less truly a living organism than a mustard seed. As the microscopic yeast plant develops and multiplies within the dough, its myriad living cells permeate the lump, and every bit of the leavened mass is capable of affecting likewise another batch of properly prepared meal. The process of leavening, or causing dough "to rise," by the fermentation of the yeast placed in the mass, is a slow one, and moreover as quiet and seemingly secret as that of the planted seed growing without the sower's further attention or concern.[634] THE HIDDEN TREASURE. "Again, the kingdom of heaven is like unto treasure hid in a field; the which when a man hath found, he hideth, and for joy thereof goeth and selleth all that he hath, and buyeth that field."[635]