Sahih Bukhari | Volume 2 | Hadith Number 149

Narrated by Ibn 'Umar
Allah's Apostle (p.b.u.h) said, "Keys of the unseen knowledge are five which nobody knows but Allah... nobody knows what will happen tomorrow; nobody knows what is in the womb; nobody knows what he will gain tomorrow; nobody knows at what place he will die; and nobody knows when it will rain."