Matthew 15:11

Not that which goes into the mouth makes a man unclean, but that which comes out of the mouth.

Acts 10:14-15

But Peter said, No, Lord; for I have never taken food which is common or unclean.

Mark 7:15

There is nothing outside the man which, going into him, is able to make him unclean: but the things which come out of the man are those which make the man unclean.

Psalm 10:7

His mouth is full of cursing and deceit and false words: under his tongue are evil purposes and dark thoughts.

Psalm 12:2

Everyone says false words to his neighbour: their tongues are smooth in their talk, and their hearts are full of deceit.

Psalm 52:2-4

Purposing destruction, using deceit; your tongue is like a sharp blade.

Psalm 58:3-4

The evil-doers are strange from the first; from the hour of their birth they go out of the true way, saying false words.

Isaiah 37:23

Against whom have you said evil and bitter things? and against whom has your voice been loud and your eyes lifted up? even against the Holy One of Israel.

Isaiah 59:3-5

For your hands are unclean with blood, and your fingers with sin; your lips have said false things, and your tongue gives out deceit.

Isaiah 59:13-15

We have gone against the Lord, and been false to him, turning away from our God, our words have been uncontrolled, and in our hearts are thoughts of deceit.

Jeremiah 9:3-6

Their tongues are bent like a bow to send out false words: they have become strong in the land, but not for good faith: they go on from evil to evil, and they have no knowledge of me, says the Lord.

Matthew 12:34-37

You offspring of snakes, how are you, being evil, able to say good things? because out of the heart's store come the words of the mouth.

Matthew 15:18-20

But the things which come out of the mouth come from the heart; and they make a man unclean.

Luke 11:38-41

And when the Pharisee saw it, he was surprised because he came to the meal without first washing himself.

Acts 11:8-9

But I said, No, Lord; for nothing common or unclean has ever come into my mouth.

Romans 3:13-14

Their throat is like an open place of death; with their tongues they have said what is not true: the poison of snakes is under their lips:

Romans 14:14

I am conscious of this, and am certain in the Lord Jesus, that nothing is unclean in itself; but for the man in whose opinion it is unclean, for him it is unclean.

Romans 14:17

For the kingdom of God is not food and drink, but righteousness and peace and joy in the Holy Spirit.

Romans 14:20

Do not let the work of God come to nothing on account of food. All things are certainly clean; but it is evil for that man who by taking food makes it hard for another.

1 Timothy 4:4-5

Because everything which God has made is good, and nothing is evil, if it is taken with praise:

Titus 1:15

To the clean in heart all things are clean: but to those who are unclean and without faith nothing is clean; they become unclean in mind and in thought.

Hebrews 13:9

Do not be turned away by different strange teachings, because it is good for your hearts to be made strong by grace, and not by meats, which were of no profit to those who took so much trouble over them.

James 3:5-8

Even so the tongue is a small part of the body, but it takes credit for great things. How much wood may be lighted by a very little fire!

2 Peter 2:18

For with high-sounding false words, making use of the attraction of unclean desires of the flesh, they get into their power those newly made free from those who are living in error;

Treasury of Scripture Knowledge

Summary

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

Bible References

That which goeth

Mark 7:15
There is nothing outside the man which, going into him, is able to make him unclean: but the things which come out of the man are those which make the man unclean.
Luke 11:38
And when the Pharisee saw it, he was surprised because he came to the meal without first washing himself.
Acts 10:14
But Peter said, No, Lord; for I have never taken food which is common or unclean.
Acts 11:8
But I said, No, Lord; for nothing common or unclean has ever come into my mouth.
Romans 14:14
I am conscious of this, and am certain in the Lord Jesus, that nothing is unclean in itself; but for the man in whose opinion it is unclean, for him it is unclean.
1 Timothy 4:4
Because everything which God has made is good, and nothing is evil, if it is taken with praise:
Titus 1:15
To the clean in heart all things are clean: but to those who are unclean and without faith nothing is clean; they become unclean in mind and in thought.
Hebrews 13:9
Do not be turned away by different strange teachings, because it is good for your hearts to be made strong by grace, and not by meats, which were of no profit to those who took so much trouble over them.

But

Matthew 15:18
But the things which come out of the mouth come from the heart; and they make a man unclean.
Matthew 12:34
You offspring of snakes, how are you, being evil, able to say good things? because out of the heart's store come the words of the mouth.
Psalm 10:7
His mouth is full of cursing and deceit and false words: under his tongue are evil purposes and dark thoughts.
Psalm 12:2
Everyone says false words to his neighbour: their tongues are smooth in their talk, and their hearts are full of deceit.
Psalm 52:2
Purposing destruction, using deceit; your tongue is like a sharp blade.
Psalm 58:3
The evil-doers are strange from the first; from the hour of their birth they go out of the true way, saying false words.
Isaiah 37:23
Against whom have you said evil and bitter things? and against whom has your voice been loud and your eyes lifted up? even against the Holy One of Israel.
Isaiah 59:3
For your hands are unclean with blood, and your fingers with sin; your lips have said false things, and your tongue gives out deceit.
Jeremiah 9:3
Their tongues are bent like a bow to send out false words: they have become strong in the land, but not for good faith: they go on from evil to evil, and they have no knowledge of me, says the Lord.
Romans 3:13
Their throat is like an open place of death; with their tongues they have said what is not true: the poison of snakes is under their lips:
James 3:5
Even so the tongue is a small part of the body, but it takes credit for great things. How much wood may be lighted by a very little fire!
2 Peter 2:18
For with high-sounding false words, making use of the attraction of unclean desires of the flesh, they get into their power those newly made free from those who are living in error;

General references

Leviticus 11:2
Say to the children of Israel: These are the living things which you may have for food among all the beasts on the earth.
Matthew 15:18
But the things which come out of the mouth come from the heart; and they make a man unclean.
Luke 12:57
And why are you, in your hearts, unable to be judges of what is right?

Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain