יִשְׂמַ֣ח צַ֭דִּיק כִּי־חָזָ֣ה נָקָ֑ם פְּעָמָ֥יו יִ֝רְחַ֗ץ בְּדַ֣ם הָרָשָֽׁע׃
The righteous shall rejoice when he seeth the vengeance; He shall wash his feet in the blood of the wicked.
Read kabbalistic (mystical) interpretation of Psalms 58:11: and classical mystical sources.