Hadith 506160
Chapter 17: Zakat - كتاب الزكاة
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي بَكْرِ بْنِ عَمْرِو بْنِ حَزْمٍ، أَنَّهُ قَالَ جَاءَ كِتَابٌ مِنْ عُمَرَ بْنِ عَبْدِ الْعَزِيزِ إِلَى أَبِي وَهُوَ بِمِنًى أَنْ لاَ يَأْخُذَ مِنَ الْعَسَلِ وَلاَ مِنَ الْخَيْلِ صَدَقَةً .
Yahya related to me from Malik that Abdullah ibn Abi Bakr ibn Amr ibn Hazim said, "A message came from Umar ibn Abd al-Aziz to my father when he was in Mina telling him not to take zakat from either honey or horses."
Reference Muwatta Malik 506160
USC-MSA web (English) reference : Book 17, Hadith 40