Thematic Bible: Tree and its fruit

"For there never is a healthy tree that bears poor fruit, nor a sickly tree that bears good fruit. For every tree is known by its fruit. People do not pick figs from thornbushes, or gather grapes from a bramble-bush. The good man, out of his good inner storehouse, brings forth what is good, the bad man, out of his bad one, what is bad. For a man's mouth usually speaks the things that fill his heart.