Yahweh forgiving the people and causing them to no longer sin is spoken of as if he would cleanse them with water. The phrase "you will be purified" can be stated in active form. Alternate translation: "I will purify you as if I were sprinkling you with pure water, and I will cause you to stop worshiping idols" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-activepassive]])