Musnad Ahmad 31:598

Yahya ibn Zakariya ibn Abi Za'idah narrated to us, he said: I heard Mujalid saying: I bear witness regarding Abu al-Waddak, that he bore witness regarding Abu Sa'id al-Khudri, that he heard him saying: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Indeed, the people of Paradise will see the people of 'Illiyyun, just as you see the brilliant star in the horizon of the sky. And indeed, Abu Bakr and Umar are among them, and they have been favored." Isma'il ibn Abi Khalid said—and he was sitting with Mujalid on the rug—: And I bear witness regarding 'Atiyyah al-'Awfi, that he bore witness regarding Abu Sa'id al-Khudri, that he heard the Prophet (peace and blessings of Allah be upon him) saying that.