O generation of vipers! - Christ here applies the argument which he had suggested in the previous verse. They were a wicked race; like poisonous reptiles, with a corrupt and evil nature. They could not be expected to speak good things - that is, to speak favorably of him and his works. As the bad fruit of a tree was the proper effect of its "nature," so were their words about him and his works the proper effect of their nature. The "abundance" or fullness of the "heart" produced the words of the lips. "Vipers" are a poisonous kind of serpents, not often a yard long, and about an inch thick, having a flat head. The males have two large teeth, through which a most deadly poison is thrown into the wound made by the bite. They are an emblem of malignity and mischief. These were strong expressions to be used by the meek and lowly Jesus; but they were not the effect of anger and malice; they were a declaration of the true character of the people with whom he was conversing - a declaration most justly deserved. See the notes at Matthew 3:7.

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 overflowings of a heart that is filled with the Holy Spirit, and running over with love to God and man.

O generation of vipers,.... Though they boasted of their being the seed of Abraham, yet their immediate ancestors were no other than vipers, deceitful, hurtful, poisonous creatures; and they were exactly like them: for though they made a fair show in the flesh, and outwardly appeared righteous, yet were inwardly full of the poison of wickedness, envy and malice; and which their pestilential breath, their blasphemy against the Spirit, fully discovered; and gave just cause and reason for so severe a reproof, and such resentment, as here made by Christ.

How can ye, being evil, speak good things? This is not to be expected, nor is it commonly and constantly done; an evil man may sometimes speak good things, or which seem to be so; but these are not his common talk; as he is, so, for the most part, is his language; his speech betrays him: and since these men were by nature evil, were destitute of the Spirit and grace of God, had no good thing in them, how should any good thing come out of them? And since they were so full of wickedness, spite and malice, it is no wonder that they belched out such blasphemous expressions concerning the miracles of Christ;

for out of the abundance of the heart the mouth speaketh: a phrase much like this is used by the Septuagint, in Ecclesiastes 2:15. "I spoke abundance", or "much in my heart"; "for the fool out of his abundance speaketh": as there is abundance of folly in him, there is much delivered out by him; and where there is abundance of wickedness in the heart, if the grace of God is wanting to restrain it, much of it will come out by the lips; as is a man's heart, ordinarily is his language.

{7} O generation of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh.

(7) Hypocrites at length betray themselves even by their own mouth.

12:34,35 Generation of vipers. Poisonous, evil and dangerous, like vipers.

How can ye, etc.? Their hearts were thoroughly evil, hence they could only speak and do evil, for out of the good treasure of the heart the mouth speaketh. On the other hand, the good man out of the good treasure of his heart bringeth forth good things.

12:34 In another kind likewise, the tree is known by its fruit - Namely, the heart by the conversation.

Margin generation

Progeny. Mt 3:7 23:33.

34. O generation of vipers-(See on [1281]Mt 3:7).

how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh-a principle obvious enough, yet of deepest significance and vast application. In Lu 6:45 we find it uttered as part of the discourse delivered after the choice of the apostles.

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.