Mujahid said concerning this verse: "Those are declared innocent of what they say": Whoever is good is free of every wicked word that he (himself) says; Allah will forgive him. And whoever is wicked is free of every righteous word that he said; Allah will throw it back at him and will not accept it from him.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19560