Repentance of an adulterer who is punished is enough for seventy people
A woman from Juhaynah came to the Prophet ﷺ while she was pregnant after having illegal sexual relations. She said: O Prophet of Allah ﷺ, I've crossed boundaries ˹with a sin˺, so lift it from me (i.e. punish me for it). The Prophet of Allahﷺ called her guardian and said: Treat her well, and when she delivers bring her to me. He did accordingly.
Then the Prophet of Allah ﷺ pronounced judgment on her and her clothes were tied around her and then he commanded and she was stoned ˹to death˺. He then prayed over her ˹dead body˺. Thereupon Umar said to him: O Prophet of Allah, you offer prayer for her, whereas she had committed adultery? Thereupon he said: "She has made such a repentance that if it were to be divided among seventy men of Madinah, it would be enough. Have you found any repentance better than this that she sacrificed her life for Allah ﷻ?"
أَنَّ امْرَأَةً مِنْ جُهَيْنَةَ أَتَتْ نَبِيَّ اللَّهِ ﷺ وَهِيَ حُبْلَى مِنَ الزِّنَى فَقَالَتْ: يَا نَبِيَّ اللَّهِ، أَصَبْتُ حَدًّا فَأَقِمْهُ عَلَىَّ۔ فَدَعَا نَبِيُّ اللَّهِ ﷺ وَلِيَّهَا فَقَالَ: «أَحْسِنْ إِلَيْهَا فَإِذَا وَضَعَتْ فَائْتِنِي بِهَ۔» فَفَعَلَ۔
فَأَمَرَ بِهَا نَبِيُّ اللَّهِ ﷺ فَشُكَّتْ عَلَيْهَا ثِيَابُهَا ثُمَّ أَمَرَ بِهَا فَرُجِمَتْ۔ ثُمَّ صَلَّى عَلَيْهَا فَقَالَ لَهُ عُمَرُ تُصَلِّي عَلَيْهَا يَا نَبِيَّ اللَّهِ وَقَدْ زَنَتْ؟ فَقَالَ: «لَقَدْ تَابَتْ تَوْبَةً، لَوْ قُسِمَتْ بَيْنَ سَبْعِينَ مِنْ أَهْلِ الْمَدِينَةِ لَوَسِعَتْهُمْ وَهَلْ وَجَدْتَ تَوْبَةً أَفْضَلَ مِنْ أَنْ جَادَتْ بِنَفْسِهَا لِلَّهِ تَعَالَى؟»