Musnad Abu Ya'la al-Mawsili 115:38

Hadaba narrated to us, Hammam narrated to us, Qatada informed us, from Anas, that the Messenger of Allah (peace be upon him) said: "There is no one among the people of Paradise who would be pleased to return to the world, even if he were to have ten times its equivalent, except for the martyr. For he would wish to return to the world and be killed ten times, because of what he sees of the merit."