Sunan an-Nasa'i 2468
سنن النسائي#2468SahihIt was narrated that Abu Hurairah said:"The Messenger of Allah said: 'A Muslim man does not have to pay Zakah on his slave or his horse
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiHasan
In-book reference: 23:34