Here God compares a person who stops sinning with one who washes his body. AT: "Repent and wash the sin from your heart like you wash the dirt from your body" (See: [[rc://en/ta/man/translate/figs-metaphor]])
God was not telling them to do their evil deeds somewhere else, but to stop doing them. AT: "stop doing the evil deeds that I see you doing" (See: [[rc://en/ta/man/translate/figs-metaphor]])