مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 769
Prayer
Suitable Dress - Section 3
وَعَنْ عَمْرِو بْنِ شُعَيْبٍ عَنْ أَبِيهِ عَنْ جَدِّهِ قَالَ: رَأَيْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يُصَلِّي حافيا ومتنعلا. رَوَاهُ أَبُو دَاوُد
‘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.
Mishkat al-Masabih, 769صَحِيح (الألباني)