Jami` at-Tirmidhi 1708
جامع الترمذي#1708Da'ifحَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا يَحْيَى بْنُ آدَمَ، عَنْ قُطْبَةَ بْنِ عَبْدِ الْعَزِيزِ، عَنِ الأَعْمَشِ، عَنْ أَبِي يَحْيَى، عَنْ مُجَاهِدٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ نَهَى رَسُولُ اللَّهِ صلى الله عليه وسلم عَنِ التَّحْرِيشِ بَيْنَ الْبَهَائِمِ .
Narrated Abu Yahya:From Mujahid from Ibn 'Abbas who said: "The Messenger of Allah (ﷺ) prohibited instigating fights between beasts
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Ahmad Muhammad ShakirDaif
Al-AlbaniDaif
Zubair Ali ZaiDaif
In-book reference: 23:40