Musnad Ahmad 30:3841

Muhammad ibn Mus'ab narrated to us, al-Awza'i narrated to us, from Yahya, from Abu Salamah, from Abu Hurayrah, from the Prophet, peace and blessings of Allah be upon him, who said: "I am the master of the children of Adam, the first for whom the earth will split open, the first intercessor, and the first whose intercession will be accepted."