حَدَّثَنَا مُحَمَّدُ بْنُ طَرِيفٍ، حَدَّثَنَا عَائِذُ بْنُ حَبِيبٍ، عَنْ حُمَيْدٍ، عَنْ أَنَسٍ، أَنَّ النَّبِيَّ ـ صلى الله عليه وسلم ـ رَأَى نُخَامَةً فِي قِبْلَةِ الْمَسْجِدِ فَغَضِبَ حَتَّى احْمَرَّ وَجْهُهُ فَجَاءَتْهُ امْرَأَةٌ مِنَ الأَنْصَارِ فَحَكَّتْهَا وَجَعَلَتْ مَكَانَهَا خَلُوقًا فَقَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ ‏"‏ مَا أَحْسَنَ هَذَا ‏"‏ ‏.‏

It was narrated from Anas that: The Prophet saw some sputum in the prayer direction of the mosque and he became so angry that his face turned red. Then a woman from among the Ansar came and scraped it off, and put some Khaluq on that spot. The Messenger of Allah said: "How good this is." Translation Not Available

Book Ref: Sunan Ibn Majah Book 4 Hadith 762
Web Ref:  Sunan Ibn Majah Vol 1 Book 4 Hadith 762