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كتاب التفسير
65  
Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh))
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The Statement of Allah: "Allah knows what every female bears, and by how much the wombs fall short (of their time or number)..." (V.13:8)
(1)
Sahih al-Bukhari 4697

Narrated Ibn `Umar:

Allah's Messenger (ﷺ) 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 Qur'an 31:34.")

حَدَّثَنِي إِبْرَاهِيمُ بْنُ الْمُنْذِرِ، حَدَّثَنَا مَعْنٌ، قَالَ حَدَّثَنِي مَالِكٌ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنِ ابْنِ عُمَرَ ـ رضى الله عنهما ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ مَفَاتِيحُ الْغَيْبِ خَمْسٌ لاَ يَعْلَمُهَا إِلاَّ اللَّهُ لاَ يَعْلَمُ مَا فِي غَدٍ إِلاَّ اللَّهُ، وَلاَ يَعْلَمُ مَا تَغِيضُ الأَرْحَامُ إِلاَّ اللَّهُ وَلاَ يَعْلَمُ مَتَى يَأْتِي الْمَطَرُ أَحَدٌ إِلاَّ اللَّهُ، وَلاَ تَدْرِي نَفْسٌ بِأَىِّ أَرْضٍ تَمُوتُ، وَلاَ يَعْلَمُ مَتَى تَقُومُ السَّاعَةُ إِلاَّ اللَّهُ ‏"‏‏.‏
Reference : Sahih al-Bukhari 4697
In-book reference : Book 65, Hadith 219
USC-MSA web (English) reference : Vol. 6, Book 60, Hadith 219
  (deprecated numbering scheme)