Sunan an Nasai
2477
Sahih+2

It was narrated that 'Ali, may Allah e pleased with him, said:"The Messenger of Allah said: 'I have exempted you from (having to pay Zakah on) horses and slaves. Pay the Zakah on your wealth, for every two hundred (Dirhams), five

SahihAbu Ghuddah
HasanAl-Albani