Matthew 15:18

But those things which proceed out of the mouth, come out of the heart, and they defile the man.

Matthew 12:34

Ye brood of vipers, how can ye, being evil, speak good things? For out of the abundance of the heart the mouth speaketh.

Matthew 15:11

Not that which goeth into the mouth defileth the man, but what cometh out of the mouth, this defileth the man.

James 3:6-10

And the tongue is a fire, a world of iniquity: it is the tongue among the members which defileth the whole body and setteth on fire the course of nature, and is set on fire of hell.

Luke 19:22

And he saith to him, Out of thy own mouth will I judge thee, thou wicked servant. Thou knewest that I am an austere man, taking up what I laid not down, and reaping what I did not sow.

Revelation 13:5-6

And there was given him a mouth speaking great things and blasphemy, and authority was given him forty and two months.

Treasury of Scripture Knowledge

Summary

But those things which proceed out of the mouth come forth from the heart; and they defile the man.

Bible References

General references

Matthew 15:11
Not that which goeth into the mouth defileth the man, but what cometh out of the mouth, this defileth the man.
Matthew 12:34
Ye brood of vipers, how can ye, being evil, speak good things? For out of the abundance of the heart the mouth speaketh.
Luke 19:22
And he saith to him, Out of thy own mouth will I judge thee, thou wicked servant. Thou knewest that I am an austere man, taking up what I laid not down, and reaping what I did not sow.
James 3:6
And the tongue is a fire, a world of iniquity: it is the tongue among the members which defileth the whole body and setteth on fire the course of nature, and is set on fire of hell.
Revelation 13:5
And there was given him a mouth speaking great things and blasphemy, and authority was given him forty and two months.