ذِكْرُ الزَّجْرِ لِلْمَرْءِ أَنْ يَتَنَخَّمَ فِي الْمَسْجِدِ مِنْ غَيْرِ أَنْ يَدْفِنَ نُخَامَتَهُ
The Messenger of Allah ﷺ said: Spitting in the mosque is a sin and it is expiated by burying the spittle. (Using translation from Abū Dāʾūd 475)
قَالَ رَسُولُ اللَّهِ ﷺ «النُّخَامَةُ فِي الْمَسْجِدِ خَطِيئَةٌ وَكَفَّارَتُهَا دَفْنُهَا»