"If you are in prayer, do not spit to your right, but rather behind you, or to your left, or beneath your left foot."(1)

In this chapter, there is also a narration from Abu Sa'id, Ibn 'Umar, Anas, and Abu Hurayrah.

The hadith of Tariq is a hasan sahih hadith, and the scholars act upon this.

I heard Al-Jarud say: I heard Waki' say: Rib'i ibn Hirash never told a lie in Islam.

And 'Abd al-Rahman ibn Mahdi said: The most reliable of the people of Kufah is Mansur ibn al-Mu'tamir.

579 - Qutaybah narrated to us, saying: Abu 'Awanah narrated to us, from Qatadah, from Anas ibn Malik, who said: The Messenger of Allah, peace and blessings be upon him, said: "Spitting in the mosque is a sin, and its expiation is to bury it."(2)

This hadith is hasan sahih.

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(1) Its chain is sahih, and it was recorded by Abu Dawud (478), Ibn Majah (1021), and al-Nasa'i 2/52, and it is in the Musnad of Ahmad (27221).
(2) Its chain is sahih, and it was recorded by al-Bukhari (415), Muslim (552), Abu Dawud (474), and al-Nasa'i 2/50-51, and it is in the Musnad of Ahmad (12062), and Sahih Ibn Hibban (1635).