(35) باب النَّهْىِ عَنِ الأَكْلِ، مِنْ لُحُومِ الأَضَاحِي بَعْدَ ثَلاَثٍ وَعَنْ إِمْسَاكِهِ
It was narrated from Ibn 'Umar that:
the Messenger of Allah forbade eating the meat of sacrificial animals after three days" (Sahih )
Reference: Sunan an-Nasa'i 4423
In-book reference: Book 43, Hadith 63
English translation: Vol. 5, Book 43, Hadith 4428