[In the Simile of the Herbs,] roots, stalks, twigs, and leaves indicate faith, precepts, meditation, and wisdom. Roots are the most important part of plants. Without roots, they cannot grow stalks, twigs, or leaves. Therefore “roots” means faith. One cannot keep the precepts without faith. Because of keeping the precepts, one can enter into the mental state of meditation and can also obtain wisdom.

Conversely, however strong the roots may be, they will eventually die if the twigs and leaves wither or if the stalks are cut. In the same way, if man does not have wisdom, his faith will become corrupt. In short, in believing in a religion, man begins with faith and attains wisdom through the precepts and meditation. However, these four steps of his religious practice are always interrelated and exist together. When any one of the four steps is lacking, his religious practice cannot be perfect, and it will not progress to the next stage. Just as a tree may be big or little, superior, middle, or low, so different people are large- or smallminded, wise or ignorant.