Adam Clarke's Commentary on the Bible - Matthew 12:34
O generation of vipers - These are apparently severe words; but they were extremely proper in reference to that execrable people to whom they were addressed: the whole verse is an inference from what was spoken before. Out of the abundance ( περισσευματος , the overflowings) of the heart - Wicked words and sinful actions may be considered as the overflowings of a heart that is more than full of the spirit of wickedness; and holy words and righteous deeds may be considered as the... read more
Adam Clarke's Commentary on the Bible - Matthew 12:33
Either make the tree good - That is, the effect will be always similar to the cause; a bad tree will produce bad fruit, and a good tree, good fruit. The works will resemble the heart: nothing good can proceed from an evil spirit; no good fruit can proceed from a corrupt heart. Before the heart of man can produce any good, it must be renewed and influenced by the Spirit of God. read more