Sahih Bukhari Volume 006, Book 060, Hadith Number 219.

Narrated By Ibn Umar : Allah's Apostle said, "The keys of Unseen are five which none knows but Allah: None knows what will happen tomorrow but Allah; none knows what is in the wombs (a male child or a female) but Allah; none knows when it will rain but Allah; none knows at what place one will die; none knows when the Hour will be established but Allah." (See The Quran 31:34.")

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