Sunan Ibn Majah
The Book On The Mosques And The Congregations — Hadith #495
حَدَّثَنَا مُحَمَّدُ بْنُ عُثْمَانَ الْعُثْمَانِيُّ أَبُو مَرْوَانَ، حَدَّثَنَا إِبْرَاهِيمُ بْنُ سَعْدٍ، عَنِ ابْنِ شِهَابٍ، عَنْ حُمَيْدِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ، عَنْ أَبِي هُرَيْرَةَ، وَأَبِي، سَعِيدٍ الْخُدْرِيِّ أَنَّهُمَا أَخْبَرَاهُ أَنَّ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ 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 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.”
Chain of Narration (Isnad)