" لاَ تَذْبَحُوا إِلاَّ مُسِنَّةً إِلاَّ أَنْ يَعْسُرَ عَلَيْكُمْ فَتَذْبَحُوا جَذَعَةً مِنَ الضَّأْنِ "
It was narrated that Jabir said: "The Messenger of Allah said: 'Do not slaughter anything but a Musinnah, unless that is difficult, in which case you can slaughter a Jadh'ah sheep."'