It is narrated from a Bedouin (desert Arab) who saw the Prophet (peace and blessings be upon him) that he said: "I saw the Prophet (peace and blessings be upon him) praying while he (peace and blessings be upon him) was wearing shoes made of camel leather. Then (during the prayer) he (peace and blessings be upon him) spat to his left and then rubbed with his shoe the spot where he (peace and blessings be upon him) had spat."
Imam Ahmad recorded this narration in the Musnad. Its chain contains an unnamed narrator (whose name is not mentioned), because of which it is weak in terms of its chain; however, the subject of praying in shoes, and, when needed, spitting to the left and wiping it away by rubbing it with the shoe, is found in other sahih hadith.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب الصلاة / 385
Hadith Gradingمحدثین:إسناده ضعيف
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :إسنادہ ضعیف » «أخرجه أحمد فى «مسنده» برقم: 20374، وأورده ابن حجر فى "المطالب العالية"، 385، وأخرجه ابن أبى شيبة فى «مصنفه» برقم: 7947»