Psalms 73:13 Midrash

אַךְ־רִ֭יק זִכִּ֣יתִי לְבָבִ֑י וָאֶרְחַ֖ץ בְּנִקָּי֣וֹן כַּפָּֽי׃

Surely in vain have I cleansed my heart, And washed my hands in innocency;