Sahih al-Bukhari 4778
Sahih al-Bukhari · Book 65: Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)) · The Statement of Allah the Exalted: "Verily, Allah! With Him (Alone) is the knowledge of the Hour..." (V.31:34)
Narrated `Abdullah bin `Umar:
حَدَّثَنَا يَحْيَى بْنُ سُلَيْمَانَ ، قَالَ حَدَّثَنِي ابْنُ وَهْبٍ ، قَالَ حَدَّثَنِي عُمَرُ بْنُ مُحَمَّدِ بْنِ زَيْدِ بْنِ عَبْدِ اللَّهِ بْنِ عُمَرَ ، أَنَّ أَبَاهُ ، حَدَّثَهُ أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ ـ رضى الله عنهما ـ قَالَ قَالَ النَّبِيُّ ـ صلى الله عليه وسلم ـ " مَفَاتِيحُ الْغَيْبِ خَمْسٌ " ثُمَّ قَرَأَ {إِنَّ اللَّهَ عِنْدَهُ عِلْمُ السَّاعَةِ} .
The Prophet (ﷺ) said, "The keys of the Unseen are five." And then he recited: 'Verily, the knowledge of the Hour is with Allah (alone).' (31.34)