The Evil Inclination, Lifelong Enemy in Midrash Tanchuma

Another interpretation of And it came to pass when Pharaoh let the people go (Exodus 13:17). This is what Scripture says: "When the LORD is pleased with a person's ways, He makes even his enemies to be at peace with him" (Proverbs 16:7). Rabbi Joshua ben Levi said: About whom does it speak? About the evil inclination. And is there a greater enemy than this? It is the way of the world that a person who dwells in a city with his fellow for one year, even if he hates him, becomes his friend. The evil inclination grows up with a person from his youth until his old age, and every single day it seeks to make him fall. And if it cannot make him fall within ten years, it makes him fall within twenty years. They said concerning Yochanan the High Priest, that he served in the high priesthood eighty years, and in the end he became a Sadducee.