But when it is sown, it grows up, and becomes greater than all plants, and shoots out great branches; so that the fowls of the air may lodge under the shadow of it.
Read Chapter 4
Ambrose of Milan
AD 397
Its seed is indeed very plain, and of little value; but if bruised or crushed it shows forth its power. So faith first seems a simple thing; but if it is bruised by its enemies it gives forth proof of its power, so as to fill others who hear or read of it with the odor of its sweetness. Our martyrs, Felix, Nabor and Victor, possessed the sweet odor of faith; but they dwelt in obscurity. When the persecution came, they laid down their arms, and bowed their necks, and being stricken by the sword they diffused to all the ends of the earth the grace of their martyrdom…. The Lord himself is the grain of mustard seed. He was without injury; but the people were unaware of him as a grain of mustard seed of which they took no notice. He chose to be bruised, that we might say: “For we are the good odor of Christ unto God.”
In the same manner, then, the catholicity of our mother becomes palpable when others who are not her sons make war on her. It is a fact that this little branch of worshipers in Africa has been broken off from the great tree which embraces the whole world in the spreading of its branches. She is in labor with them in charity, that they may return to the root without which they cannot have true life.
It is up to us to sow this mustard seed in our minds and let it grow within us into a great tree of understanding reaching up to heaven and elevating all our faculties; then it will spread out branches of knowledge, the pungent savor of its fruit will make our mouths burn, its fiery kernel will kindle a blaze within us inflaming our hearts, and the taste of it will dispel our unenlightened repugnance. Yes, it is true: a mustard seed is indeed an image of the kingdom of God. Christ is the kingdom of heaven. Sown like a mustard seed in the garden of the virgin’s womb, he grew up into the tree of the cross whose branches stretch across the world. Crushed in the mortar of the passion, its fruit has produced seasoning enough for the flavoring and preservation of every living creature with which it comes in contact. As long as a mustard seed remains intact, its properties lie dormant; but when it is crushed they are exceedingly evident. So it was with Christ; he chose to have his body crushe...