Musnad Ahmad 788:212

Abu Salamah al-Khuza'i narrated to us, he said: 'Abd al-'Aziz ibn Muhammad informed us, from 'Amr ibn Abi 'Amr, from al-Muttalib, from Abu Musa al-Ash'ari, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever loves his worldly life harms his Hereafter, and whoever loves his Hereafter harms his worldly life. So, prefer that which remains over that which perishes."