From Sahih Bukhari (Hadith 4627):
Narrated `Abdullah:Allah's Messenger (ﷺ) said, "The keys of the Unseen are five: Verily with Allah (Alone) is the knowledge of the Hour He sends down the rain and knows what is in the wombs. No soul knows what it will earn tomorrow, and no soul knows in what land it will die. Verily, Allah is All-Knower, All-Aware
Reference: Bukhari 4627