Musnad Ahmad 32:1307

'Abdullah ibn Yazid narrated to us, Sulayman narrated to us, from Thabit, from Anas, who said: Harithah, the son of my paternal aunt, set out—he did not set out for battle—and an arrow struck him and killed him. His mother came to the Messenger of Allah, peace and blessings of Allah be upon him, and said: "O Messenger of Allah, my son Harithah; if he is in Paradise, I will be patient and seek reward." He said: "O mother of Harithah, it is many gardens, and Harithah is in the highest Firdaws."