עָקֹ֥ב הַלֵּ֛ב מִכֹּ֖ל וְאָנֻ֣שׁ ה֑וּא מִ֖י יֵדָעֶֽנּוּ׃
The heart is deceitful above all things, And it is exceeding weak—who can know it?
Rashi on Jeremiah
The heart is deceitful Full of pretext and deceit of all evil.
Rashi on Jeremiah
and when it is sick an expression of sickness, and this is its sickness.
Rashi on Jeremiah
who recognizes it? He thinks, “Who recognizes it?” I, the Lord, search it.