‘Amr b. Shu'aib, on his father's authority, said that his grandfather declared he had seen God’s Messenger praying both barefoot and wearing sandals. Abu Dawud transmitted it.
Hadith Referenceمشكوة المصابيح / كتاب الصلاة / 769
Hadith Gradingالألبانی:صَحِيح | زبیر علی زئی:إسناده حسن
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «إسناده حسن، رواه أبو داود (653) [وابن ماجه: 1038]»