Ibn ‘Umar reported God’s Messenger as saying, “The keys of the unseen are five.” He then recited, “God has knowledge of the Hour, and He sends down the rain . . .” (Al-Qur’an; 31:34). Bukhari transmitted it.

وَعَنِ ابْنِ عُمَرَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ " مَفَاتِيحُ الْغَيْبِ خَمْسٌ ثُمَّ قَرَأَ: (إِنَّ اللَّهَ عِنْدَهُ عِلْمُ السَّاعَةِ وَيُنَزِّلُ الْغَيْثَ) الْآيَة. رَوَاهُ البُخَارِيّ