مُوَطَّأُ مَالِكٍ
Muwatta Malik 617
Zakat
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، أَنَّهُ قَالَ سَأَلْتُ سَعِيدَ بْنَ الْمُسَيَّبِ عَنْ صَدَقَةِ الْبَرَاذِينِ، فَقَالَ وَهَلْ فِي الْخَيْلِ مِنْ صَدَقَةٍ
Yahya related to me from Malik that Abdullah ibn Dinar said, "I asked Said ibn al-Musayyab about zakat on work-horses, and he said, 'Is there any zakat on horses ?' "
Arabic/English book reference: Book 17, Hadith 41