from As-Suddi who said: "Someone who heard from 'Ali, narrated about him saying: 'When this Ayah was revealed: "And whether you disclose what is in yourselves or conceal it, Allah will call you to account for it. Then He forgives whom He wills and He punishes whom He wills (2:284).' - we were very distressed about it.' He said: 'We said: "Something occurs in ourselves to one of us, and he will be taken to account for it, and we do not know what of it he will be pardoned for, and what of it he will not be pardoned for." So this Ayah was revealed: Allah does not burden a soul beyond what it can bear, for it, is what it has earned, and against it, is what it has wrought. (Its meaning is recorded by Muslim, while the chain for this version is weak)  

سَمِعَ عَلِيًّا يَقُولُ لَمَّا نَزَلَتْ هَذِهِ الآيَةُ (إِنْ تُبْدُوا مَا فِي أَنْفُسِكُمْ أَوْ تُخْفُوهُ يُحَاسِبْكُمْ بِهِ اللَّهُ فَيَغْفِرُ لِمَنْ يَشَاءُ وَيُعَذِّبُ مَنْ يَشَاءُ ) الآيَةَ أَحْزَنَتْنَا قَالَ قُلْنَا يُحَدِّثُ أَحَدُنَا نَفْسَهُ فَيُحَاسَبُ بِهِ لاَ نَدْرِي مَا يُغْفَرُ مِنْهُ وَلاَ مَا لاَ يُغْفَرُ فَنَزَلَتْ هَذِهِ الآيَةُ بَعْدَهَا فَنَسَخَتْهَا ( لاَ يُكَلِّفُ اللَّهُ نَفْسًا إِلاَّ وُسْعَهَا لَهَا مَا كَسَبَتْ وَعَلَيْهَا مَا اكْتَسَبَتْ )