Psalm 36:3

The words of their mouths are wicked and deceitful; they fail to act wisely or do good. 

The words of their mouths 
Psalm 10:7  His mouth is full of lies and threats; trouble and evil are under his tongue.

are wicked and deceitful 
Job 5:13  "He catches the wise in their craftiness, and the schemes of the wily are swept away."
Psalm 5:5-6  The arrogant cannot stand in your presence. You hate all who do wrong; you destroy those who tell lies. The bloodthirsty and deceitful you, LORD, detest."
Psalm 5:9  Not a word from their mouth can be trusted; their heart is filled with malice. Their throat is an open grave; with their tongues they tell lies.
Psalm 43:1  Vindicate me, my God, and plead my cause against an unfaithful nation. Rescue me from those who are deceitful and wicked.
Psalm 144:7-8  Reach down your hand from on high; deliver me and rescue me from the mighty waters, from the hands of foreigners whose mouths are full of lies, whose right hands are deceitful. (also Psalm 144:11)
Isaiah 44:19-20  No one stops to think, no one has the knowledge or understanding to say, "Half of it I used for fuel; I even baked bread over its coals, I roasted meat and I ate. Shall I make a detestable thing from what is left? Shall I bow down to a block of wood?" Such a person feeds on ashes; a deluded heart misleads him; he cannot save himself, or say, "Is not this thing in my right hand a lie?"

they fail to act wisely or do good 
Psalm 94:8  Take notice, you senseless ones among the people; you fools, when will you become wise?
Jeremiah 4:22  "My people are fools; they do not know me. They are senseless children; they have no understanding. They are skilled in doing evil; they know not how to do good."
Jeremiah 13:23  "Can an Ethiopian change his skin or a leopard his spots? Neither can you do good who are accustomed to doing evil."
Amos 3:10  "They do not know how to do right," declares the LORD, "who store up in their fortresses what they have plundered and looted."

(parentheses are mine)

Scriptures taken from the Holy Bible, New International Version® NIV®, Copyright© 1973, 1978, 1984, 2011 by Biblica, Inc.® Used by permission. All rights reserved worldwide. 
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