Musnad Abu Ya'la al-Mawsili 159:109

Ibrahim ibn Ziyad Sablan narrated to us, Abu Mu'awiyah narrated to us, Muhammad ibn Ishaq narrated to us, from Jamil ibn Abi Maymunah, from 'Ata' ibn Yazid al-Laythi, from Abu Hurayrah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Whoever goes out for Hajj and dies, Allah writes for him the reward of the pilgrim until the Day of Resurrection. Whoever goes out for 'Umrah and dies, Allah writes for him the reward of the one performing 'Umrah until the Day of Resurrection. Whoever goes out as a warrior in the way of Allah and dies, Allah writes for him the reward of the warrior until the Day of Resurrection."