Musnad Ahmad 31:477

Muhammad ibn Ubayd narrated to us, Ismail—meaning Ibn Abi Khalid—narrated to us, from Atiyyah al-Awfi, from Abu Sa’id al-Khudri, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Indeed, the people of 'Illiyyun are seen by those who are below them, just as the star is seen in the horizon of the sky. And indeed, Abu Bakr and Umar are among them, and they are blessed." Abu Abd al-Rahman said: I heard my father say: I heard Sufyan ibn Uyaynah say regarding the hadith of the Prophet (peace and blessings of Allah be upon him): He says: "And they are blessed," he said: "And they are of them."