Offspring of vipers! how can ye speak good things, being wicked? For of the abundance of the heart the mouth speaks.
The Pharisees had just credited the Lord's power over demons to Satan. Here He turns from their charge to the source that produced it. His answer moves from fruit back to tree, from speech back to the heart. Can anyone speak good words while the inner spring stays bad?
The Tree Behind the Fruit
The Lord had just told them to make the tree good and its fruit good, or the tree bad and its fruit bad. Here He goes behind the sin they had committed to what produced it.
The Lord now turns from the sin these Pharisees were doing, the blasphemy against the Holy Spirit, to its cause, the spring from which the evil comes... The Searcher of hearts, He who understands the thoughts from far off, uncovers the real condition of these men and the condition of man in general. The tree is bad, the fruit must be bad. The tree must be made good, and that denotes a change, and the fruit will be good.
"Brood of Vipers"
The name He gives them is not random abuse. It points to poison, and John had already used the same word for the same people.
All we learn from the passages that speak of the viper is that its bite was poisonous... John the Baptist called the crowd who came to be baptised "a brood of vipers." The Lord uses the same name for the scribes and Pharisees. It shows how deadly their opposition was.
Why Good Words Are Impossible
The question "how can you speak good?" is not a call to try harder. The mouth can only pass on what the heart holds — and this is true of religious people too.
If the heart did not contain these evils the mouth could never give them forth. Here then we have an insight into the human heart. Notice also that this terrible quotation comes in the apostle's description of religious Jews, not in his account of pagan Gentiles... Yet it is one of the hardest lessons of all to learn that the heart of every man is wicked beyond cure.
Fine language is no evidence of a good heart:
The language of the cultured, religious, unsaved man may be fine and polished, sweet and pleasant. But it comes from an evil heart, so it can never please God.
Speech as Evidence
If speech comes out of what fills the heart, then speech becomes evidence. Small, unguarded words tell more than big, controlled actions.
"Out of the abundance of the heart the mouth speaks." An impatient word betrays the heart. A blow I may restrain and yet utter the word.
The test also works in reverse. What you talk about most shows what has your heart.
When we find people taken up with one thing more than another, we may be sure that that object has the heart. We are always marked by what we seek. And so our words matter.
Words That Justify or Condemn
The Lord goes on to say that people will answer for every careless word. Read in context, the words in question are words about Him.
These idle words betray the heart's rejection of Jesus, and they slight the Holy Spirit's testimony to Him. "By your words you will be justified, and by your words you will be condemned." It is with the mouth that a person makes the confession that leads to salvation. Words that leave out Jesus prove that the heart prefers its sin to Him.
The Cure Is Not the Tongue
Since the mouth only reports, guarding the lips alone will never work. The remedy is to change what the heart is full of.
Again and again He warned those around Him of the danger of uncontrolled speech, and Scripture repeats the warning everywhere... The way to reach this goal is for Christ and His things to fill our hearts. Then our talk will flow out of what fills us.
And the test is not the hour when we are trying to sound spiritual:
"In word." This is a very big test for each of us, for "out of the abundance of the heart, the mouth speaks." Whatever sits on the throne in our hearts will surely govern our speech. The question is not how we speak about divine things for one short hour in a Bible reading. The question is what our talk is like at home, at work, among our friends, in company, and at all times.
Summary
- Root — the Lord traces their blasphemy back to its spring. The fruit was bad because the tree was bad. Only a changed tree bears good fruit.
- Poison — "Brood of vipers" is the name John used first. It marks how deadly their opposition was, not just bad manners.
- Impossible — the mouth only gives out what the heart holds. An evil heart cannot produce good words, however polished the language.
- Evidence — words are the index of the heart. An impatient word betrays what a restrained hand hides. What we talk about most shows what owns us.
- Verdict — words that leave out Jesus prove the heart prefers its sin to Him. The cure is a heart filled with Christ — tested at home and at work, not for one religious hour.