Musnad Abu Ya'la al-Mawsili 116:10

Ahmad narrated to us, Abu 'Amir al-Qaysi narrated to us, Shu'bah narrated to us, from Qatadah, from Anas, from the Prophet (peace be upon him), who said: "There is no one who enters Paradise and would be pleased to exit it, even if he possessed everything that is on the earth, except for the martyr. For he wishes to return and be killed ten times because of what he sees of the honor."