Chapter on the prohibition of spitting in the mosque, the command to remove it from there if found, and the command to keep the mosque free from filth.

The reader: In the name of Allah, the Most Gracious, the Most Merciful.
Praise be to Allah, Lord of the worlds, and may peace and blessings be upon our Prophet Muhammad, and upon his family and all his Companions.
He (may Allah have mercy on him) said: "Chapter on the prohibition of spitting in the mosque, the command to remove it from there if found, and the command to keep the mosque free from filth.
Anas (may Allah be pleased with him) reported that the Messenger of Allah (peace and blessings be upon him) said

Spitting in the Masjid is a sin, and its expiation is to bury it.

البصاق في المسجد خطيئة وكفارتها دفنها

Sunan an-Nasa'i 723Sahih (Darussalam)

Agreed upon by al-Bukhari and Muslim.
And Aisha (may Allah be pleased with her) reported

The Messenger of Allah (ﷺ) saw spittle or snot or sputum, sticking to the wall towards Qiblah and scratched it off.

أن رسول الله صلى الله عليه وسلم رأى في جدار القلبة مخاطا أو بزاقا أو نخامة فحكه

Riyad as-Salihin 1694

Agreed upon by al-Bukhari and Muslim.
And Anas (may Allah be pleased with him) reported that the Messenger of Allah (peace and blessings be upon him) said

These mosques are not the places meant for urine and filth, but are only for the remembrance of Allah, prayer and the recitation of the Qur'an

إن هذه المساجد لا تصلح لشيء من هذا البول ولا القذر إنما هي لذكر الله تعالى وقراءة القرآن

Sahih Muslim 285

or as the Messenger of Allah (peace and blessings be upon him) said. Narrated by Muslim."

The Shaykh : In the name of Allah, the Most Gracious, the Most Merciful.
The author (may Allah have mercy on him) established this chapter in his book *Riyad al-Saliheen* to clarify the obligation of keeping mosques free from harm, filth, spittle, and the like. Then he mentioned the hadith of Anas and the hadith of Aisha (may Allah be pleased with them both).
The hadith of Anas is that the Prophet (peace and blessings be upon him) said meaning a sin. meaning if it falls from a person, he should bury it.
In his saying (peace and blessings be upon him) there is evidence for the prohibition of spitting in the mosque, whether a person spits out phlegm, or blows his nose in the mosque, or induces it in the mosque, or the like. It is a sin for two reasons:
The first reason is that it is a nuisance to the worshippers. A worshipper might prostrate on it without being aware of it, or he might feel disgust when he sees it and his soul would be repelled by it, thus causing him harm.
And the first reason is that it is a humiliation of the houses of Allah the Exalted, which Allah the Exalted commanded to be raised and His name to be mentioned in them. It is not permissible for a person to spit in the mosque. But if he did so, its expiation is to bury it if it is on the ground, and its expiation is to scrape it off if it is on the wall or the like, based on the hadith of Aisha (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) saw spittle or spit on the qiblah of the mosque and scraped it off. So the expiation for that, if it is on the ground, is to bury it, and if it is on the wall, is to scrape it off until it is removed.
As for our mosques now, as you see, they are carpeted. The expiation for that is to wipe it with a handkerchief until it is removed. But I say, originally, it is not permissible for you to spit in the mosque. But if it happens, this is its expiation.
Then he mentioned the hadith of Aisha (may Allah be pleased with her) This indicates that if a person sees harm or filth in the mosque, he should remove it.
As for the second hadith of Anas, it is about the story of The Messenger (peace and blessings be upon him) clarified that these mosques are not suitable for any harm or filth. So the believer must respect the houses of Allah, not throw harm or filth into them, and not raise his voice in them. Rather, he should be well-mannered, because the mosques are the houses of Allah and the abode of the angels. And success is from Allah.