Matthew 12:35

"A good man out of his good treasure," saith He, "bringeth forth good things, and an evil man out of his evil treasure bringeth forth evil things." For think not by any means, saith He, that it is so in respect of wickedness only, for in goodness also the same occurs: for there too the virtue within is more than the words without. By which He signified, that both they were to be accounted more wicked than their words indicated, and Himself more perfectly good than His sayings declared. And He calls it "a treasure," indicating its abundance.

What He says, The good man out of the good treasure of his heart, & c. is either pointed against the Jews, that seeing they blasphemed God, what treasure in their heart must that be out of which such blasphemy proceeded; or it is connected with what had gone before, that like as a good man cannot bring forth evil things, nor an evil man good things, so Christ cannot do evil works, nor the Devil good works.

Or the words, Generation of vipers, may be taken as signifying children, or imitators of the Devil, because they had wilfully spoken against good works, which is of the Devil, and thence follows, Out of the abundance of the heart the mouth speaketh. That man speaks out of the abundance of the heart who is not ignorant with what intention his words are uttered; and to declare his meaning more openly He adds, A good man out of the good treasure of his heart bringeth forth good things. The treasure of the heart is the intention of the thoughts, by which the Judge judges that work which is produced, so that sometimes though the outward work that is shown seem great, yet because of the carelessness of a cold heart, they receive a little reward from the Lord.