This parable and the Parable of the Mustard Seed are a pair. They tell much the same story, but with somewhat different emphases. Understanding the Parable of the Leaven is very straightforward. In fact, it is so straightforward that it is amazing that most commentators give a wrong interpretation for it. In the Parable of the Mustard Seed, Jesus taught that the small, powerful, and simple faith that He planted would grow into a large and corrupt institution. The Parable of the Leaven focuses on the corruption.