NET
6 They devise unjust schemes; they disguise a well-conceived plot. Man’s inner thoughts cannot be discovered.
Darby
6 They devise iniquities: We have it ready, the plan is diligently sought out. And each one's inward [thought] and heart is deep.
KJV
6 They search out iniquities; they accomplish a diligent search: both the inward [thought] of every one [of them], and the heart, [is] deep.