Messenger of Allah ﷺ saw some expectoration on the wall of the mosque; he took gravel and scraped it off and said, "If anyone of you wanted to spit, he should neither spit in front of him nor on his right but could spit either on his left or under his left foot."  

أَنَّ رَسُولَ اللَّهِ ﷺ رَأَى نُخَامَةً فِي حَائِطِ الْمَسْجِدِ فَتَنَاوَلَ رَسُولُ اللَّهِ ﷺ حَصَاةً فَحَتَّهَا ثُمَّ قَالَ إِذَا تَنَخَّمَ أَحَدُكُمْ فَلاَ يَتَنَخَّمْ قِبَلَ وَجْهِهِ وَلاَ عَنْ يَمِينِهِ وَلْيَبْصُقْ عَنْ يَسَارِهِ أَوْ تَحْتَ قَدَمِهِ الْيُسْرَى  

The Prophet ﷺ said, "None of you should spit in front or on his right but he could spit either on his left or under his foot."  

قَالَ النَّبِيُّ ﷺ لاَ يَتْفِلَنَّ أَحَدُكُمْ بَيْنَ يَدَيْهِ وَلاَ عَنْ يَمِينِهِ وَلَكِنْ عَنْ يَسَارِهِ أَوْ تَحْتَ رِجْلِهِ