Musnad Ahmad 30:1813

Qutaybah narrated to us, Layth ibn Sa'd narrated to us, from Ibn 'Ajlan, from al-Qa'qa' ibn Hakim, from Abu Salih, from Abu Hurayrah, that the Prophet, peace and blessings of Allah be upon him, said: "The heart of the old man remains young in the love of two things: longevity of life, and abundance of wealth."