Everyone knows the traditional, time-worn but timeless definition of a parable: "an earthly story with a heavenly meaning." That old saw still manages to buzz with the energy of the almost mystical ability Jesus' parables have to invite listeners in and to open their eyes and their hearts.

Yet in the first of the two parables read in today's gospel text, Mark 4:26-29, we will see that such a definition may actually lead us away from the central focus of the parable itself. Just what that focus is remains a matter of considerable scholarly discussion. For example, unlike most of Jesus' other well-known parables, there is no strong agreement on the title for this parable text: "The Growth of the Seed," "The Seed That Grows by Itself," "The Seed Growing Secretly," "The Patient Husbandman," "T…