
Basil the Great
Catena Aurea · Lukasevangelium 6
For a good tree bringeth not forth corrupt fruit; neither doth a corrupt tree bring forth good fruit. For every tree is known by his own fruit. For of thorns men do not gather figs, nor of a bramble bush gather they grapes. A good man out of the good treasure of his heart bringeth forth that which is good; and an evil man out of the evil treasure of his heart bringeth forth that which is evil: for of the abundance of the heart his mouth speaketh.
The quality of the words shews the heart from which they proceed, plainly manifesting the inclination of our thoughts. Hence it follows, For out of the abundance of the heart the mouth speaketh.