Charles Ellicott Commentary Psalms 64:6

"They search out iniquities; We have accomplished, [say they], a diligent search: And the inward thought and the heart of every one is deep." — Psalms 64:6 (ASV)

They search out iniquities — i.e., they plan wicked schemes.

They accomplish a diligent search. —See margin, which indicates the difficulty in this clause. The versions and some manuscripts also suggest a corruption of the text. Read “They have completed their subtle measures” (literally, the planned plan).