Musnad Ahmad 32:312

Yazid ibn Harun narrated to us, Hammad ibn Salamah informed us, from Thabit al-Bunani, from Anas ibn Malik, that Harithah went out as a spectator, and an arrow struck him and killed him. His mother said: "O Messenger of Allah, you know my position regarding Harithah. If he is in Paradise, I will be patient, otherwise, you will see what I shall do." He said: "O mother of Harithah, it is not one Paradise, but many gardens, and Harithah is in the best of them," or he said: "In the highest of Firdaws" — Yazid was in doubt.