Narrated Abdullah ibn Abbas:

The Prophet ﷺ said: If anyone has sexual intercourse with an animal, kill him and kill it along with him. I (Ikrimah) said: I asked him (Ibn Abbas): What offence can be attributed to the animal/ He replied: I think he (the Prophet) disapproved of its flesh being eaten when such a thing had been done to it.

Abu Dawud said: This is not a strong tradition.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ النُّفَيْلِيُّ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ مُحَمَّدٍ، حَدَّثَنِي عَمْرُو بْنُ أَبِي عَمْرٍو، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، قَالَ قَالَ رَسُولُ اللَّهِ ﷺ
" مَنْ أَتَى بَهِيمَةً فَاقْتُلُوهُ وَاقْتُلُوهَا مَعَهُ " . قَالَ قُلْتُ لَهُ مَا شَأْنُ الْبَهِيمَةِ قَالَ مَا أُرَاهُ إِلاَّ قَالَ ذَلِكَ أَنَّهُ كَرِهَ أَنْ يُؤْكَلَ لَحْمُهَا وَقَدْ عُمِلَ بِهَا ذَلِكَ الْعَمَلُ . قَالَ أَبُو دَاوُدَ لَيْسَ هَذَا بِالْقَوِيِّ .