"Allah has certainly conferred a favor upon the believers when He sent among them a Messenger from themselves, reciting to them His verses and purifying them"—meaning: He makes them righteous. "And teaching them the Book"—the Qur'an—"and the Wisdom"—the Sunnah—"although they had been, before"—before the Prophet, peace be upon him, came to them—"in clear error"—evident.