وَٱلَّذِينَ لَا يَدْعُونَ مَعَ ٱللَّهِ إِلَٰهًا ءَاخَرَ وَلَا يَقْتُلُونَ ٱلنَّفْسَ ٱلَّتِى حَرَّمَ ٱللَّهُ إِلَّا بِٱلْحَقِّ وَلَا يَزْنُونَ … إِلَّا مَن تَابَ وَءَامَنَ وَعَمِلَ عَمَلًا صَٰلِحًا فَأُو۟لَٰٓئِكَ يُبَدِّلُ ٱللَّهُ سَيِّـَٔاتِهِمْ حَسَنَٰتٍ
"They do not call upon another god together with God; they do not kill the soul God has made inviolable, save by right; and they do not commit fornication… Except for the one who repents, believes and does a righteous deed: for those, God changes their evil deeds into good ones."
Three grave acts are enumerated, and an exception follows them. And the scope of the exception must be recorded: it covers all three.
The root ب-د-ل: to put one thing in the place of another. The root was treated at al-Wāqiʿa 56/61 (an nubaddila amthālakum).
I record this as an observation: the sentence does not speak of erasing — it speaks of exchanging. That is, the past is not lifted away; the column it is entered in is changed.
And the same line was treated at al-Zumar 39/53 (lā taqnaṭū min raḥmati'llāhi inna'llāha yaghfiru'dh-dhunūba jamīʿā). The two verses are read together: the one forbids despair, the other states what the return receives in exchange.
وَمَن تَابَ وَعَمِلَ صَٰلِحًا فَإِنَّهُۥ يَتُوبُ إِلَى ٱللَّهِ مَتَابًا (71) — and the return itself is reinforced once more, by the absolute object.