Musnad Abu Ya'la al-Mawsili 160:248

Abu Hammam narrated to us, Abd al-Rahim ibn Sulayman narrated to us, that Zakariya informed them, from Amir, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "I am the first one to raise his head after the second blast. Then, behold, Musa is clinging to the Throne. I do not know if he was like that, or if it was after the blast."