Matthew 15:18

But the things which go forth out of the mouth, come out of the heart, and they are the things which defile a man:

Matthew 12:34

Ye broods of vipers, how can ye speak good things, yourselves being wicked? for out of the abundance of the heart the mouth speaketh.

Matthew 15:11

not that which goeth into the mouth defileth a man; but what cometh out of the mouth, that defileth the man.

James 3:6-10

And the tongue is a fire, a world of iniquity: in such manner is the tongue placed among our members, that it defileth all the body, and setteth on fire the circle of nature; and is set on fire of hell.

Luke 19:22

And he said to him, Out of thine 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 to him a mouth speaking great things and blasphemies; and there was given to him authority 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 a man; but what cometh out of the mouth, that defileth the man.
Matthew 12:34
Ye broods of vipers, how can ye speak good things, yourselves being wicked? for out of the abundance of the heart the mouth speaketh.
Luke 19:22
And he said to him, Out of thine 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: in such manner is the tongue placed among our members, that it defileth all the body, and setteth on fire the circle of nature; and is set on fire of hell.
Revelation 13:5
And there was given to him a mouth speaking great things and blasphemies; and there was given to him authority to make war forty-two months.