Sunan an-Nasai 19167
In-book no 4431أَخْبَرَنِي مُحَمَّدُ بْنُ آدَمَ، قَالَ حَدَّثَنَا عَبْدَةُ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ فَاطِمَةَ، عَنْ أَسْمَاءَ، قَالَتْ ذَبَحْنَا عَلَى عَهْدِ رَسُولِ اللَّهِ صلى الله عليه وسلم فَرَسًا وَنَحْنُ بِالْمَدِينَةِ فَأَكَلْنَاهُ .
It was narrated that Asma said: "We slaughtered (naharna) a horse during the time of the Messenger of Allah while we were in Al-Madinah, and we ate it." (Sahih )