The believer's fear that his good deeds may be lost Sahih Muslim 119 b

Arabic hadith text
وَحَدَّثَنَا قَطَنُ بْنُ نُسَيْرٍ، حَدَّثَنَا جَعْفَرُ بْنُ سُلَيْمَانَ، حَدَّثَنَا ثَابِتٌ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ كَانَ ثَابِتُ بْنُ قَيْسِ بْنِ شَمَّاسٍ خَطِيبَ الأَنْصَارِ فَلَمَّا نَزَلَتْ هَذِهِ الآيَةُ ‏.‏ بِنَحْوِ حَدِيثِ حَمَّادٍ ‏.‏ وَلَيْسَ فِي حَدِيثِهِ ذِكْرُ سَعْدِ بْنِ مُعَاذٍ ‏.‏
Translation
This hadith has been narrated on the authority of Anas b. Malik by another chain of transmitters in which these words are found

Thabit b. Qais was the orator of the Ansar, when this verse was revealed: the rest of the hadith is the same with the exception that there is no mention of Sa'd b. Mu'adh in it.