Hope of repentance for grave sins

Some people from among the polytheists had killed, and had done so many times, and had committed zina, and had done so many times. They came to Muhammad ﷺ and said, “What you say and call to is certainly good, if only you would tell us that there is an expiation for what we have done.” Then it was revealed: “And those who do not call upon another god along with Allah ﷻ, and do not kill the soul which Allah ﷻ has forbidden except by right, and do not commit zina,” and it was revealed: “Say, ‘O My servants who have transgressed against themselves, do not despair of the mercy of Allah ﷻ.’”

أَنَّ نَاسًا مِنْ أَهْلِ الشِّرْكِ كَانُوا قَدْ قَتَلُوا وَأَكْثَرُوا، وَزَنَوْا وَأَكْثَرُوا، فَأَتَوْا مُحَمَّدًا ﷺ فَقَالُوا: إِنَّ الَّذِي تَقُولُ وَتَدْعُو إِلَيْهِ لَحَسَنٌ، لَوْ تُخْبِرُنَا أَنَّ لِمَا عَمِلْنَا كَفَّارَةً. فَنَزَلَ: ﴿وَالَّذِينَ لاَ يَدْعُونَ مَعَ اللَّهِ إِلَهًا آخَرَ وَلاَ يَقْتُلُونَ النَّفْسَ الَّتِي حَرَّمَ اللَّهُ إِلاَّ بِالْحَقِّ وَلاَ يَزْنُونَ﴾، وَنَزَلَ: ﴿قُلْ يَا عِبَادِيَ الَّذِينَ أَسْرَفُوا عَلَى أَنْفُسِهِمْ لاَ تَقْنَطُوا مِنْ رَحْمَةِ اللَّهِ﴾