Compiled by Imam Muhammad al-Bukhari
حَدَّثَنَا أَبُو النُّعْمَانِ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ عُبَيْدِ اللَّهِ بْنِ أَبِي بَكْرِ بْنِ أَنَسٍ، عَنْ أَنَسِ بْنِ مَالِكٍ ـ رضى الله عنه ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " إِنَّ اللَّهَ وَكَّلَ فِي الرَّحِمِ مَلَكًا فَيَقُولُ يَا رَبِّ نُطْفَةٌ، يَا رَبِّ عَلَقَةٌ، يَا رَبِّ مُضْغَةٌ، فَإِذَا أَرَادَ أَنْ يَخْلُقَهَا قَالَ يَا رَبِّ، أَذَكَرٌ أَمْ يَا رَبِّ أُنْثَى يَا رَبِّ شَقِيٌّ أَمْ سَعِيدٌ فَمَا الرِّزْقُ فَمَا الأَجَلُ فَيُكْتَبُ كَذَلِكَ فِي بَطْنِ أُمِّهِ ".
The Prophet (ﷺ) said, "Allah has appointed an angel in the womb, and the angel says, 'O Lord! A drop of discharge (i.e. of semen), O Lord! a clot, O Lord! a piece of flesh.' And then, if Allah wishes to complete the child's creation, the angel will say. 'O Lord! A male or a female? O Lord! wretched or blessed (in religion)? What will his livelihood be? What will his age be?' The angel writes all this while the child is in the womb of its mother."