Musnad Ahmad 30:2019

Ishaq ibn Isa narrated to us, Ibn Lahi'ah narrated to us, from Abd al-Rahman al-A'raj, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "I have been granted victory through awe, and I have been given the concluding words [of speech]. And while I was sleeping, I was brought the keys to the treasures of the earth, and they were placed in my hand."