"Ali said: 'A cow is for seven.' I said: "And if it gives birth?' He said: 'Then slaughter its offspring with it.' I said: 'What if it is lame?' He said: 'When it has reached the place of ritual.' I said: 'What if it has a broken horn?' He said: 'There is no harm, we were ordered' - or - 'The Messenger of Allah ﷺ ordered us, to check the two eyes and the two ears.'"  

اذْبَحْ وَلَدَهَا مَعَهَا قُلْتُ فَالْعَرْجَاءُ قَالَ إِذَا بَلَغَتِ الْمَنْسِكَ قُلْتُ فَمَكْسُورَةُ الْقَرْنِ قَالَ لاَ بَأْسَ أُمِرْنَا أَوْ أَمَرَنَا رَسُولُ اللَّهِ ﷺ أَنْ نَسْتَشْرِفَ الْعَيْنَيْنِ وَالأُذُنَيْنِ  

"The Messenger of Allah ﷺ prohibited that an animal with a A'dab (stump) horn or ear should be slaughtered as a sacrifice." Qatadah (one of the narrators) said: "So I mentioned this to Sa'eed bin Al-Musayyab and he said: 'The A'dab is that which equals or more than that.'"  

نَهَى رَسُولُ اللَّهِ ﷺ أَنْ يُضَحَّى بِأَعْضَبِ الْقَرْنِ وَالأُذُنِ قَالَ قَتَادَةُ فَذَكَرْتُ ذَلِكَ لِسَعِيدِ بْنِ الْمُسَيَّبِ فَقَالَ الْعَضْبُ مَا بَلَغَ النِّصْفَ فَمَا فَوْقَ ذَلِكَ