Mat 12:35 A good man out of the good treasure of the heart brings forth good things: and an evil man out of the evil treasure brings forth evil things.

Most of the vocabulary in this verse comes from the previous verse. Again, the contrast is not between "good" (agathos) and "evil," (poneros) , which are poor translation, but between the worthless and the useful, the cowardly and the brave, useless and the beneficial. And again, "the heart," (kardia) is the seat of feelings that motivate action.

"Treasure" is thêsauros, which means a "storage area" and "treasury." Also meaning a "strong room," "a granary," "a safe," or "a cavern." It is not the valuables themselves, but the place where they are kept, and the basis for our word, "thesaurus."

"Brings forth" is ekballô, which means "cast out," "throw away," "lose," and "produce." Earlier in this chapter, this was the word used to describe "casting out" devils, so Christ (as is so often lost in translation) making a play on words. He is still in the process of defending himself against the charge of "casting out devils by the power of Beelzebub," but here he uses the term in its much less common meaning of "to produce." For example, this word is applied to women to describe giving birth to children (another form of "casting out" devils?)

My alternative translation: A useful man produces useful things from his storage of productive feelings. A worthless man produces useless things from his storage of worthless feelings.

Inherent in this statement is the idea that, by being productive and creating value, we also create a feeling of being valuable. Our sense of being valuable leads us to create more value in a virtuous cycle. People that are worthless get caught on the other side of this cycle. Their sense of worthlessness makes them into cynics and critics and prevents them from producing anything valuable.