39.الزُّمَر

لِيُكَفِّرَ اللّٰهُ عَنۡهُمۡ اَسۡوَاَ الَّذِىۡ عَمِلُوۡا وَيَجۡزِيَهُمۡ اَجۡرَهُمۡ بِاَحۡسَنِ الَّذِىۡ كَانُوۡا يَعۡمَلُوۡنَ‏

So that Allah may remove from them errors which they did and may grant them the reward for the pious deeds they used to do.