Musannaf Ibn Abi Shayba 27:353

Abu Khalid al-Ahmar narrated to us, from Humayd, from Anas, from the Prophet (peace and blessings of Allah be upon him), who said: "I entered Paradise, and suddenly I was at a palace of gold. I said, 'To whom does this belong?' They said, 'To a young man from Quraysh.' I thought that it was me, so I said, 'To whom is it?' They said, 'To Umar.'"