Obligatory Charity Tax (Zakat)

Bukhari :: Book 2 :: Volume 24 :: Hadith 569

Narrated Ibn Abbas :

The Prophet saw a dead sheep which had been given in charity to a freed slavegirl of Maimuna, the wife of the Prophet . The Prophet said, "Why don't you get the benefit of its hide?" They said, "It is dead." He replied, "Only to eat (its meat) is illegal."