Musnad Ahmad 1017:62

Zayd ibn al-Hubab narrated to us, Husayn ibn Waqid narrated to me, Abdullah ibn Buraydah informed me, he said: I heard my father, Buraydah, say: The Messenger of Allah (peace and blessings of Allah be upon him) woke up in the morning and called for Bilal. He said: "O Bilal, by what did you precede me to Paradise? I have never entered Paradise but that I heard the rustling of your footsteps in front of me. I entered Paradise last night and heard the rustling of your footsteps, and I came upon a palace of gold, elevated and overlooking. I said: 'Whose is this palace?' They said: 'For a man from the Arabs.' I said: 'I am an Arab, whose is this palace?' They said: 'For a man from the Muslims of the nation of Muhammad.' I said: 'I am Muhammad, whose is this palace?' They said: 'For Umar ibn al-Khattab.'" The Messenger of Allah (peace and blessings of Allah be upon him) then said: "Were it not for your protective jealousy, O Umar, I would have entered the palace." He (Umar) said: "O Messenger of Allah, I would never be jealous regarding you." He (the Prophet) said to Bilal: "By what did you precede me to Paradise?" He said: "I have never broken my ablution but that I performed ablution and prayed two rak'ahs." The Messenger of Allah (peace and blessings of Allah be upon him) said: "By this."