New Living Translation
As they plot their crimes, they say, “We have devised the perfect plan!” Yes, the human heart and mind are cunning.

American Standard Version
They search out iniquities; We have accomplished,'say they , a diligent search: And the inward thought and the heart of every one is deep.

Berean Study Bible
They devise injustice and say, “We have perfected a secret plan.” For the inner man and the heart are mysterious.

Douay-Rheims Bible
They have searched after iniquities: they have failed in their search. Man shall come to a deep heart:

English Revised Version
They search out iniquities; We have accomplished, say they, a diligent search: and the inward thought of every one, and the heart, is deep.

King James Bible
They search out iniquities; they accomplish a diligent search: both the inward thought of every one of them, and the heart, is deep.

World English Bible
They plot injustice, saying, "We have made a perfect plan!" Surely man's mind and heart are cunning.

Young's Literal Translation
They search out perverse things, 'We perfected a searching search,' And the inward part of man, and the heart are deep.

Psalm 64:6 Additional Translations ...