34 You brood of vipers! how can you speak good, when you are evil? For out of the abundance of the heart the mouth speaks. 35 The good man out of his good treasure brings forth good, and the evil man out of his evil treasure brings forth evil. 36 I tell you, on the day of judgment men will render account for every careless word they utter;
Matthew Henry's Commentary on Matthew 12:34-36
Commentary on Matthew 12:33-37
(Read Matthew 12:33-37)
Men's language discovers what country they are of, likewise what manner of spirit they are of. The heart is the fountain, words are the streams. A troubled fountain, and a corrupt spring, must send forth muddy and unpleasant streams. Nothing but the salt of grace, cast into the spring, will heal the waters, season the speech, and purify the corrupt communication. An evil man has an evil treasure in his heart, and out of it brings forth evil things. Lusts and corruptions, dwelling and reigning in the heart, are an evil treasure, out of which the sinner brings forth bad words and actions, to dishonour God, and hurt others. Let us keep constant watch over ourselves, that we may speak words agreeable to the Christian character.