Narrated Abu Huraira:

The Prophet was asked about donkeys and he replied, "Nothing has been revealed to me regarding donkeys except this comprehensive Verse which includes everything: "So whoever does good equal to the weight of an atom (or a smallest ant) shall see it;
And whoever, does evil equal to the weight of an atom or a smallest ant) shall see it.' (99.7-8)

حَدَّثَنَا يَحْيَى بْنُ سُلَيْمَانَ، قَالَ حَدَّثَنِي ابْنُ وَهْبٍ، قَالَ أَخْبَرَنِي مَالِكٌ، عَنْ زَيْدِ بْنِ أَسْلَمَ، عَنْ أَبِي صَالِحٍ السَّمَّانِ، عَنْ أَبِي هُرَيْرَةَ، رضى الله عنه سُئِلَ النَّبِيُّ ﷺ عَنِ الْحُمُرِ فَقَالَ " لَمْ يُنْزَلْ عَلَىَّ فِيهَا شَىْءٌ إِلاَّ هَذِهِ الآيَةُ الْجَامِعَةُ الْفَاذَّةُ فَمَنْ يَعْمَلْ مِثْقَالَ ذَرَّةٍ خَيْرًا يَرَهُ * وَمَنْ يَعْمَلْ مِثْقَالَ ذَرَّةٍ شَرًّا يَرَهُ".