Ibn Hibban

Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates this statement of the Noble Prophet (peace and blessings of Allah be upon him): "The keys of knowledge are five, which none knows except Allah Almighty: No person knows what will come forth from the womb, only Allah knows; and no person knows what will happen tomorrow, only Allah knows; no one knows when it will rain, only Allah knows. No person knows where he will die, only Allah knows. No person knows when the Hour (Day of Judgment) will come, only Allah knows."