'Abdullah bin Shakhkhir reported on the authority of his father that he said: I said prayer with the Messenger of Allah (ﷺ) and saw him spitting and rubbing it off with his shoe.
Hadith Referenceصحيح مسلم / كتاب المساجد ومواضع الصلاة / 554
'Abdullah bin Shakhkhir narrated it on the authority of his father that he said prayer with the Messenger of Allah (ﷺ) , and he spat and then rubbed it off with his left shoe.
Hadith Referenceصحيح مسلم / كتاب المساجد ومواضع الصلاة / 554
Abu al-Ala reported on the authority of his father: I came to the Messenger of Allah ﷺ who was saying prayer. He spat beneath his left foot.
Shaykh Umar Farooq Saeedi
482. Commentary: Spitting, phlegm, and nasal discharge do not invalidate the prayer, and on soft ground, a person should rub it away with his left foot.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 482