Musannaf Ibn Abi Shayba 11:48

Waki’ narrated to us, Yazid narrated to us, from Ibrahim ibn al-‘Ala’ Abu Harun al-Ghanawi, from a man called Muslim ibn Shaddad, from ‘Ubayd ibn ‘Umayr, from Ubayy ibn Ka’b, who said: The martyrs are in domes in gardens in the courtyard of Paradise. A whale and a bull are sent to them, and they wrestle with each other, and they amuse themselves with them. When they need something, one of them slaughters the other, and they eat from it, and they find the taste of everything from Paradise [in it].