Sahih Muslim
The Book of Destiny (Kitab-ul-Qadr)
Book Number: 033 / Hadith Number: 6416
Abdullah b. 'Amr b. al-'As reported: I heard Allah's Messenger (may peace be upon him) as saying: Allah ordained the measures (of quality) of the creation fifty thousand years before He created the heavens and the earth, as His Throne was upon water.