Musnad Abu Ya'la al-Mawsili 115:215

Narrated to us Zuhayr, narrated to us Abu ‘Amir, from Shu’bah, from Qatadah, from Anas, that the Prophet (peace and blessings of Allah be upon him) said: "There is no one who enters Paradise who would wish to exit it, even if he had everything that is upon the earth, except for the martyr. For he wishes to return and be killed ten times because of what he sees of the honor."