كتاب الزهد والرقائق
55  
The Book of Zuhd and Softening of Hearts
(14)
Chapter: The Prohibition Of Praising if It Involves Exaggeration And There Is The Fear That It May Be A Source Of Temptation (Fitnah) For The One Who Is Praised
(14)
باب النَّهْىِ عَنِ الْمَدْحِ، إِذَا كَانَ فِيهِ إِفْرَاطٌ وَخِيفَ مِنْهُ فِتْنَةٌ عَلَى الْمَمْدُوحِ
Sahih Muslim 3002 b

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 (ﷺ) 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 ‏"‏ ‏.‏
Reference : Sahih Muslim 3002b
In-book reference : Book 55, Hadith 88
USC-MSA web (English) reference : Book 42, Hadith 7143
  (deprecated numbering scheme)