عَنْ جَابِرٍ رَضِيَ اللَّهُ عَنْهُ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ لَا تَذْبَحُوا إِلَّا مُسِنَّةً إِلَّا أَنْ تَعْسُرَ عَلَيْكُمْ فَتَذْبَحُوا جَذَعَةً مِنَ الضَّأْنِ
It is narrated from Sayyiduna Jabir (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: You should only slaughter a two-toothed animal, but if this becomes difficult for you, then you may slaughter a jadha’ (one-year-old) sheep.