Sahih al-Bukhari 4479
Narrated Abu Huraira:
The Prophet ﷺ said, "It was said to the children of Israel, 'Enter the gate (of the town), prostrate (in humility) and say: Hittatun (i.e. repentance) i.e. O Allah! Forgive our sins.' But they entered by dragging themselves on their buttocks, so they did something different (from what they had been ordered to do) and said, 'Hittatun,' but added, "A grain in a hair."
حَدَّثَنِي مُحَمَّدٌ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ مَهْدِيٍّ، عَنِ ابْنِ الْمُبَارَكِ، عَنْ مَعْمَرٍ، عَنْ هَمَّامِ بْنِ مُنَبِّهٍ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ عَنِ النَّبِيِّ ﷺ قَالَ " قِيلَ لِبَنِي إِسْرَائِيلَ ادْخُلُوا الْبَابَ سُجَّدًا وَقُولُوا حِطَّةٌ فَدَخَلُوا يَزْحَفُونَ عَلَى أَسْتَاهِهِمْ، فَبَدَّلُوا وَقَالُوا حِطَّةٌ، حَبَّةٌ فِي شَعَرَةٍ ".