(32) باب ذِكْرِ نَهْىِ النَّبِيِّ صلى الله عليه وسلم عَنْ أَنْ يَبْصُقَ الرَّجُلُ بَيْنَ يَدَيْهِ أَوْ عَنْ يَمِينِهِ وَهُوَ فِي صَلاَتِهِ
It was narrated from Abu Sa'eed Al-Khudri that the Prophet (ﷺ) saw some spittle in the Qiblah of the Masjid. He scratched it off with a pebble and forbade a man to spit to his front or to his right. He said:
"Let him spit to his left or beneath his left foot."
Reference: Sunan an-Nasa'i 725
In-book reference: Book 8, Hadith 38
English translation: Vol. 1, Book 8, Hadith 726