Psalm 12:2

They speak falsehood every one with his neighbor: With flattering lip, and with a double heart, do they speak.

Psalm 41:6

And if he come to see me , he speaketh falsehood; His heart gathereth iniquity to itself: When he goeth abroad, he telleth it.

Romans 16:18

For they that are such serve not our Lord Christ, but their own belly; and by their smooth and fair speech they beguile the hearts of the innocent.

Psalm 10:7

His mouth is full of cursing and deceit and oppression: Under his tongue is mischief and iniquity.

Jeremiah 9:8

Their tongue is a deadly arrow; it speaketh deceit: one speaketh peaceably to his neighbor with his mouth, but in his heart he layeth wait for him.

1 Chronicles 12:33

Of Zebulun, such as were able to go out in the host, that could set the battle in array, with all manner of instruments of war, fifty thousand, and that could order the battle array, and were not of double heart.

Psalm 5:9

For there is no faithfulness in their mouth; Their inward part is very wickedness; Their throat is an open sepulchre; They flatter with their tongue.

Psalm 28:3

Draw me not away with the wicked, And with the workers of iniquity; That speak peace with their neighbors, But mischief is in their hearts.

Psalm 144:8

Whose mouth speaketh deceit, And whose right hand is a right hand of falsehood.

James 1:8

a doubleminded man, unstable in all his ways.

Psalm 36:3-4

The words of his mouth are iniquity and deceit: He hath ceased to be wise and to do good.

Psalm 38:12

They also that seek after my life lay snares for me ; And they that seek my hurt speak mischievous things, And meditate deceits all the day long.

Psalm 52:1-4

Why boastest thou thyself in mischief, O mighty man? The lovingkindness of God endureth continually.

Psalm 55:21

His mouth was smooth as butter, But his heart was war: His words were softer than oil, Yet were they drawn swords.

Psalm 59:12

For the sin of their mouth, and the words of their lips, Let them even be taken in their pride, And for cursing and lying which they speak.

Psalm 62:4

They only consult to thrust him down from his dignity; They delight in lies; They bless with their mouth, but they curse inwardly. Selah

Psalm 144:11

Rescue me, and deliver me out of the hand of aliens, Whose mouth speaketh deceit, And whose right hand is a right hand of falsehood.

Proverbs 20:19

He that goeth about as a tale-bearer revealeth secrets; Therefore company not with him that openeth wide his lips.

Proverbs 29:5

A man that flattereth his neighbor Spreadeth a net for his steps.

Jeremiah 9:2-6

Oh that I had in the wilderness a lodging-place of wayfaring men; that I might leave my people, and go from them! for they are all adulterers, an assembly of treacherous men.

Ezekiel 12:24

For there shall be no more any false vision nor flattering divination within the house of Israel.

1 Thessalonians 2:5

For neither at any time were we found using words of flattery, as ye know, nor a cloak of covetousness, God is witness;

Treasury of Scripture Knowledge

Summary

They speak vanity every one with his neighbour: with flattering lips and with a double heart do they speak.

A double heart

Bible References

Flattering

Psalm 5:9
For there is no faithfulness in their mouth; Their inward part is very wickedness; Their throat is an open sepulchre; They flatter with their tongue.
Psalm 28:3
Draw me not away with the wicked, And with the workers of iniquity; That speak peace with their neighbors, But mischief is in their hearts.
Psalm 62:4
They only consult to thrust him down from his dignity; They delight in lies; They bless with their mouth, but they curse inwardly. Selah
Proverbs 20:19
He that goeth about as a tale-bearer revealeth secrets; Therefore company not with him that openeth wide his lips.
Proverbs 29:5
A man that flattereth his neighbor Spreadeth a net for his steps.
Ezekiel 12:24
For there shall be no more any false vision nor flattering divination within the house of Israel.
Romans 16:18
For they that are such serve not our Lord Christ, but their own belly; and by their smooth and fair speech they beguile the hearts of the innocent.
1 Thessalonians 2:5
For neither at any time were we found using words of flattery, as ye know, nor a cloak of covetousness, God is witness;

A double heart

1 Chronicles 12:33
Of Zebulun, such as were able to go out in the host, that could set the battle in array, with all manner of instruments of war, fifty thousand, and that could order the battle array, and were not of double heart.

General references

Genesis 29:19
And Laban said, It is better that I give her to thee, than that I should give her to another man. Abide with me.
Judges 16:6
And Delilah said to Samson, Tell me, I pray thee, wherein thy great strength lieth, and wherewith thou mightest be bound to afflict thee.
Habakkuk 1:3
Why dost thou show me iniquity, and look upon perverseness? for destruction and violence are before me; and there is strife, and contention riseth up.
Acts 12:22
And the people shouted,'saying , The voice of a god, and not of a man.

American Standard Version Public Domain