Bulugh al-Maram #712

Abu Hurairah (RAA) narrated that the Messenger of Allah (ﷺ) said: “No Zakah is to be paid on one’s horse (that he rides) or one’s slave.” Related by Al-Bukhari. Muslim also has the narration, “There is no Zakah to be paid on one’s slave, except for Zakat-ul-Fitr (which is paid at the end of Ramadan, and a Muslim must pay it on behalf of all of those he is responsible for).”