Narrated Anas: Abu Bakr wrote to me what Allah had ordered His Apostle (about Zakat) which goes: Neither an old nor a defected animal, nor a male-goat may be taken as Zakat except if the Zakat collector wishes (to take it).
Hadith Referenceصحيح البخاري / كتاب الزكاة / 1455
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة