Hadith 518270
Chapter 58: Sadaqa - كتاب الصدقة
وَحَدَّثَنِي مَالِكٌ، عَنْ زَيْدِ بْنِ أَسْلَمَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " أَعْطُوا السَّائِلَ وَإِنْ جَاءَ عَلَى فَرَسٍ " .
Malik related to me from Zayd ibn Aslam that the Messenger of Allah, may Allah bless him and grant him peace, said, "Give to a beggar even if he comes on a horse."
Reference Muwatta Malik 518270
USC-MSA web (English) reference : Book 58, Hadith 3