
John Chrysostom
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.
(Hom. 42. in Matt.) But although the fruit is caused by the tree, yet it brings to us the knowledge of the tree, because the distinctive nature of the tree is made evident by the fruit, as it follows, For every tree is known by its fruit.