33 “Either make the tree good and its fruit good, or make the tree bad and its fruit bad; for the tree is known by its fruit. 34 You brood of vipers, how can you, being evil, speak what is good? For the mouth speaks out of that which fills the heart. 35 The good man brings out of his good treasure what is good; and the evil man brings out of his evil treasure what is evil. 36 But I tell you that every careless word that people speak, they shall give an accounting for it in the day of judgment. 37 For by your words you will be justified, and by your words you will be condemned.”

Conduct reveals character. Jesus here speaks wisdom as if by proverbs. There is no greater indicator of the state of a person’s heart than what comes out of his mouth. Even seemingly insignificant words, carelessly spoken testify to the inner thinking of a man.

Jesus’ words hold true, first of all, for Himself. His outward comment (“You brood of vipers, how can you being evil …) shows His inner thinking concerning His detractors. He has passed judgment, based on their outward behavior. The Pharisees (who had just accused Him of satanic power and authority) were intrinsically evil in their hearts, despite their outward “good show” of religiosity. This should be as obvious as concluding from the shape and taste of an apple picked from a tree that the tree itself is therefore an apple tree—so the words spoken by a person lead us to draw certain conclusions regarding the character of his heart. In the case of Pharisees, Jesus simply followed the evidence (the fruit) to where it led (the heart).

In this immediate context, the proverbial statement is applied, though, to what one says about Jesus and His miracles—namely that such comments uncover his or her heart concerning Jesus. When one asks, “Could this be the Son of David?” (vs. 23) it speaks of hearts open to the evidence of Jesus’ true identity. When one “speaks a word against the Son of man” (vs. 32), this identifies the evil state of his or her heart. It can be no other way. How often do we object when others form an opinion or judgment about us, but then we allow ourselves this same prerogative. We hear their words and conclude certain things.

Jesus projects this principle ahead to the judgment seat of God. The things we have said will be held up as evidence of our inner intentions as we stand before a holy God, whose Word, “…judges the thoughts and intentions of the heart…” (Heb 4:12b). Our words and our heart are not just incidentally connected—that is why people have a hard time forgetting our careless words.

Lord, my tongue is like a wildfire (James 3:5). Help me not to take my own words lightly, but follow them where they lead – to my heart.