Musnad Ahmad 1048
It was narrated from Jurayy bin Kulaib, that he heard `Ali (رضي الله عنه) say:
The Messenger of Allah (ﷺ) forbade sacrificing an animal that has lost most of its horn or ear. Qatadah said: I mentioned that to Sa’eed bin al-Musayyab and he said. [That refers to] one that has lost half or more (of its horn or ear).
حَدَّثَنَا عَبْدُ الْوَهَّابِ، قَالَ سُئِلَ سَعِيدٌ عَنْ الْأَعْضَبِ، هَلْ يُضَحَّى بِهِ فَأَخْبَرَنَا عَنْ قَتَادَةَ، عَنْ جُرَيِّ بْنِ كُلَيْبٍ، رَجُلٍ مِنْ قَوْمِهِ أَنَّهُ سَمِعَ عَلِيًّا، رَضِيَ اللَّهُ عَنْهُ يَقُولُ نَهَى رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَنْ يُضَحَّى بِأَعْضَبِ الْقَرْنِ وَالْأُذُنِ قَالَ قَتَادَةُ فَذَكَرْتُ ذَلِكَ لِسَعِيدِ بْنِ الْمُسَيَّبِ فَقَالَ الْعَضَبُ النِّصْفُ فَأَكْثَرُ مِنْ ذَلِكَ‏.‏