وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ عَمِّهِ أَبِي سُهَيْلِ بْنِ مَالِكٍ، عَنْ أَبِيهِ، عَنْ كَعْبِ الأَحْبَارِ، أَنَّ رَجُلاً، نَزَعَ نَعْلَيْهِ فَقَالَ لِمَ خَلَعْتَ نَعْلَيْكَ لَعَلَّكَ تَأَوَّلْتَ هَذِهِ الآيَةَ ‏{‏فَاخْلَعْ نَعْلَيْكَ إِنَّكَ بِالْوَادِي الْمُقَدَّسِ طُوًى‏}‏ قَالَ ثُمَّ قَالَ كَعْبٌ لِلرَّجُلِ أَتَدْرِي مَا كَانَتْ نَعْلاَ مُوسَى قَالَ مَالِكٌ لاَ أَدْرِي مَا أَجَابَهُ الرَّجُلُ فَقَالَ كَعْبٌ كَانَتَا مِنْ جِلْدِ حِمَارٍ مَيِّتٍ ‏.‏

Yahya related to me from Malik from his paternal uncle Abu Suhaylibn Malik from his father that Kab al-Ahbar said to a man who took offhis sandals, "Why have you taken off your sandals? Perhaps you haveinterpreted this ayat, 'Remove your sandals. You are in the purevalley of Tuwa?' (Sura 20 ayat 12) Do you know what the sandals ofMusa were?" Malik (the father of Abu Suhayl) said, "I do notknow what the man answered." Kab said, "They were made from the skinof a dead donkey." Translation Not Available

Book Ref: Muwatta Imam Malik Book 48 Hadith 1670
Web Ref:  Muwatta Imam Malik Book 48 Hadith 16