Musnad Ahmad 30:1706

Yahya ibn Ishaq narrated to us, Hammad ibn Salamah informed us, from Thabit, from Abu Rafi’, from Abu Hurairah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever enters Paradise shall be in bliss, he shall not despair, his clothes shall not wear out, and his youth shall not fade. In Paradise, there is that which no eye has seen, no ear has heard, and has not occurred to the heart of any human."