Musannaf Ibn Abi Shayba 27:319

Isma'il ibn 'Ulayyah narrated to us, from Yunus, from al-Hasan, who said: A man said to 'Umar, "O best of people!" He replied, "I am not the best of people." The man said, "By Allah, I have never seen a man better than you." He asked, "Have you not seen Abu Bakr?" The man said, "No." He said, "If you had said 'yes,' I would have punished you." And 'Umar said, "Who is it that has set me between myself and Abu Bakr? A day of Abu Bakr is better than the family of 'Umar."