Note 2 at Mk. 4:31: Indeed, the mustard seed is very tiny, and yet when fully grown, it can attain a height of 10 feet or more. It is amazing that the smallest of all seeds among herbs can produce the largest of all trees among herbs. This illustrates the Church's growth from small beginnings to a kingdom that will fill all the earth (Dan. 2:34-35,44).

This parable can also be applied on a personal level. Just as the kingdom of God must grow, there is growth in our own personal lives also (Acts 9:22; Eph. 4:15; 2 Th. 1:3; 1 Pet. 2:2; 2 Pet. 3:18). A seed must grow downward for nourishment before it can grow upward. The root system of the seed is not visible, as is the tree, but it is essential. It is easy to become so impatient waiting for the visible fruit that we neglect our roots (see note 5 at Mk. 4:16, p. 137).