حَدَّثَنَا يَحْيَى بْنُ حَبِيبِ بْنِ عَرَبِيٍّ، حَدَّثَنَا خَالِدٌ، - يَعْنِي ابْنَ الْحَارِثِ - عَنْ مُحَمَّدِ بْنِ عَجْلاَنَ، عَنْ عِيَاضِ بْنِ عَبْدِ اللَّهِ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ يُحِبُّ الْعَرَاجِينَ وَلاَ يَزَالُ فِي يَدِهِ مِنْهَا فَدَخَلَ الْمَسْجِدَ فَرَأَى نُخَامَةً فِي قِبْلَةِ الْمَسْجِدِ فَحَكَّهَا ثُمَّ أَقْبَلَ عَلَى النَّاسِ مُغْضَبًا فَقَالَ ‏"‏أَيَسُرُّ أَحَدَكُمْ أَنْ يُبْصَقَ فِي وَجْهِهِ إِنَّ أَحَدَكُمْ إِذَا اسْتَقْبَلَ الْقِبْلَةَ فَإِنَّمَا يَسْتَقْبِلُ رَبَّهُ جَلَّ وَعَزَّ وَالْمَلَكُ عَنْ يَمِينِهِ فَلاَ يَتْفُلْ عَنْ يَمِينِهِ وَلاَ فِي قِبْلَتِهِ وَلْيَبْصُقْ عَنْ يَسَارِهِ أَوْ تَحْتَ قَدَمِهِ فَإِنْ عَجِلَ بِهِ أَمْرٌ فَلْيَقُلْ هَكَذَا ‏"‏ ‏.‏ وَوَصَفَ لَنَا ابْنُ عَجْلاَنَ ذَلِكَ أَنْ يَتْفُلَ فِي ثَوْبِهِ ثُمَّ يَرُدَّ بَعْضَهُ عَلَى بَعْضٍ ‏.‏
Translation
Abu Sa’id al-khudri said

The Prophet (ﷺ) used to love cudgels (or sticks) and there would constantly be one in his hand. He entered the mosque and saw sputum in the qiblah of the mosque, so he scraped it off. Then he turned to the people in anger and said, "Would any of you like to have someone spit in his face? When any of you faces the qiblah, he is facing his Lord, and the angel is on his right. So let him not spit to his right, nor toward his qiblah, but let him spit to his left or beneath his foot. If he is rushed by an urgent matter, then let him do like this." Ibn 'Ajlan described this for us as spitting in his garment, then rubbing part of it against the other.