Sahih Muslim , Book 42, Hadith 7143 (USC-MSA) ⓘ
Hammam b. al-Harith reported that a person began to praise 'Uthman and Miqdad sat upon his knee; and he was a bulky person and began to throw pebbles upon his (flatterer's) face. Thereupon 'Uthman said: What is the matter with you? And he said: Verily, Allah's Messenger said: When you see those who shower (undue) praise (upon others), throw dust upon their faces.
وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، وَمُحَمَّدُ بْنُ بَشَّارٍ، - وَاللَّفْظُ لاِبْنِ الْمُثَنَّى - قَالاَ حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، عَنْ مَنْصُورٍ، عَنْ إِبْرَاهِيمَ، عَنْ هَمَّامِ بْنِ الْحَارِثِ، أَنَّ رَجُلاً، جَعَلَ يَمْدَحُ عُثْمَانَ فَعَمِدَ الْمِقْدَادُ فَجَثَا عَلَى رُكْبَتَيْهِ - وَكَانَ رَجُلاً ضَخْمًا - فَجَعَلَ يَحْثُو فِي وَجْهِهِ الْحَصْبَاءَ فَقَالَ لَهُ عُثْمَانُ مَا شَأْنُكَ فَقَالَ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " إِذَا رَأَيْتُمُ الْمَدَّاحِينَ فَاحْثُوا فِي وُجُوهِهِمُ التُّرَابَ " .
also referenced under: Book 55, Hadith 88 (In-Book) & Hadith 3002 (Reference)