I saw Wathila bin Asqa praying in the mosque of Damascus. He spat under his left foot and then rubbed it with his foot. When he finished, I said, "You are one of the companions of the Messenger of Allah ﷺ, yet you spit in the mosque?"He replied, "This is how I saw the Messenger of Allah ﷺ do it."
قال حدثنا هاشم قال حدثنا أبو فضالة الفرج قال حدثنا
رأيت واثلة بن الأسقع يصلي في مسجد دمشق فبزق تحت رجله اليسرى ثم عركها برجله فلما انصرف قلت أنت من أصحاب رسول الله ﷺ تبزق في المسجد قال هكذا رأيت رسول الله ﷺ يفعل
Its isnad is daif due to the unknown status of Abu Saeed al-Himyari al-Shami, for the two hadith masters Dhahabi and Ibn Hajar both declared him unknown. He is of unknown reliability but known identity. There is some weakness in Faraj bin Fadala, but he is not daif here, for were it not for the unknown status of Abu Saeed, the hadith would be sahih, since he narrates from the Levantine narrators. However, the hadith is sahih, for Muslim narrated something similar to it, 1/390, no. 554, in the Book of Masjids, chapter on the prohibition of spitting in the masjid, and Nasai, 2/52, no. 727.