“The Messenger of Allah ﷺ said: ‘Whoever fasts Ramadan and spends its nights in prayer, out of faith and in hope of reward, his previous sins will be forgiven.’” (Using translation from Ibn Mājah 1326)
قَالَ رَسُولُ اللهِ ﷺ مَنْ صَامَ رَمَضَانَ إِيمَانًا وَاحْتِسَابًا غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ