Musnad Ahmad 31:3

Hushaym narrated to us, Ali ibn Zayd narrated to us, from Abu Nadrah, from Abu Sa’id, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "I am the master of the children of Adam on the Day of Resurrection, and it is no boast. And I am the first for whom the earth will split open on the Day of Resurrection, and it is no boast. And I am the first intercessor on the Day of Resurrection, and it is no boast."