יַֽחְפְּֽשׂוּ־עוֹלֹ֗ת תַּ֭מְנוּ חֵ֣פֶשׂ מְחֻפָּ֑שׂ וְקֶ֥רֶב אִ֝֗ישׁ וְלֵ֣ב עָמֹֽק׃
They search out iniquities, they have accomplished a diligent search; even in the inward thought of every one, and the deep heart.
Read midrashic interpretation of Psalms 64:7: and classical rabbinic exegesis.