The Messenger of Allah saw some sputum on the wall of the mosque. He picked up a stone and scraped it off, then he said, "If anyone of you needs to spit, he should not spit in fro not of him or to his right; let him spit to his right; let him spit to his left or under his left foot."  

عَنْ أَبِي هُرَيْرَةَ وَأَبِي سَعِيدٍ الْخُدْرِيِّ أَنَّهُمَا أَخْبَرَاهُ أَنَّ رَسُولَ اللَّهِ ﷺ رَأَى نُخَامَةً فِي جِدَارِ الْمَسْجِدِ فَتَنَاوَلَ حَصَاةً فَحَكَّهَا ثُمَّ قَالَ إِذَا تَنَخَّمَ أَحَدُكُمْ فَلاَ يَتَنَخَّمَنَّ قِبَلَ وَجْهِهِ وَلاَ عَنْ يَمِينِهِ وَلْيَبْزُقْ عَنْ شِمَالِهِ أَوْ تَحْتَ قَدَمِهِ الْيُسْرَى  

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."  

أَنَّ النَّبِيَّ ﷺ رَأَى نُخَامَةً فِي قِبْلَةِ الْمَسْجِدِ فَغَضِبَ حَتَّى احْمَرَّ وَجْهُهُ فَجَاءَتْهُ امْرَأَةٌ مِنَ الأَنْصَارِ فَحَكَّتْهَا وَجَعَلَتْ مَكَانَهَا خَلُوقًا فَقَالَ رَسُولُ اللَّهِ ﷺ مَا أَحْسَنَ هَذَا  

"The Messenger of Allah saw some sputum in the prayer direction of the mosque, when he was praying in front of the people. He scratched it off, then when the prayer was over, he said: 'When anyone of you is performing prayer, Allah is before him, so none of you should spit toward the front while praying.'"  

رَأَى رَسُولُ اللَّهِ ﷺ نُخَامَةً فِي قِبْلَةِ الْمَسْجِدِ وَهُوَ يُصَلِّي بَيْنَ يَدَىِ النَّاسِ فَحَتَّهَا ثُمَّ قَالَ حِينَ انْصَرَفَ مِنَ الصَّلاَةِ إِنَّ أَحَدَكُمْ إِذَا كَانَ فِي الصَّلاَةِ كَانَ اللَّهُ قِبَلَ وَجْهِهِ فَلاَ يَتَنَخَّمَنَّ أَحَدُكُمْ قِبَلَ وَجْهِهِ فِي الصَّلاَةِ  

The Prophet scratched some spittle from the prayer direction of the mosque.  

أَنَّ النَّبِيَّ ﷺ حَكَّ بُزَاقًا فِي قِبْلَةِ الْمَسْجِدِ