Matthew 15:18

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

Matthew 12:34

O race of vipers, how can ye speak good things, who are yourselves so wicked? 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 that which cometh out of the mouth, this polluteth the man.

James 3:6-10

And the tongue is a fire, a world of iniquity: so is the tongue among our several parts, defiling the whole body, inflaming the course of nature, and is set on fire by hell.

Luke 19:22

But he said 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 and blasphemous things, and power was given him to make war forty 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 that which cometh out of the mouth, this polluteth the man.
Matthew 12:34
O race of vipers, how can ye speak good things, who are yourselves so wicked? for out of the abundance of the heart the mouth speaketh.
Luke 19:22
But he said 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: so is the tongue among our several parts, defiling the whole body, inflaming the course of nature, and is set on fire by hell.
Revelation 13:5
And there was given him a mouth speaking great and blasphemous things, and power was given him to make war forty two months.