Muwatta Malik
Book 58, Hadith 13
Arabic hadith text
حَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " لاَ تَحِلُّ الصَّدَقَةُ لآلِ مُحَمَّدٍ إِنَّمَا هِيَ أَوْسَاخُ النَّاسِ " .
Translation
Yahya related to me from Malik that he heard that the Messengerof Allah, may Allah bless him and grant him peace, said, "Sadaqa tothe family of Muhammad is not halal. It is only people's impurities."