The Prophet ﷺ said, "Allah puts an angel in charge of the uterus and the angel says, 'O Lord, (it is) semen! O Lord, (it is now ) a clot! O Lord, (it is now) a piece of flesh.' And then, if Allah wishes to complete its creation, the angel asks, 'O Lord, (will it be) a male or a female? A wretched (an evil doer) or a blessed (doer of good)? How much will his provisions be? What will his age be?' So all that is written while the creature is still in the mother's womb."

عَنِ النَّبِيِّ ﷺ قَالَ وَكَّلَ اللَّهُ بِالرَّحِمِ مَلَكًا فَيَقُولُ أَىْ رَبِّ نُطْفَةٌ أَىْ رَبِّ عَلَقَةٌ أَىْ رَبِّ مُضْغَةٌ فَإِذَا أَرَادَ اللَّهُ أَنْ يَقْضِيَ خَلْقَهَا قَالَ أَىْ رَبِّ ذَكَرٌ أَمْ أُنْثَى أَشَقِيٌّ أَمْ سَعِيدٌ فَمَا الرِّزْقُ فَمَا الأَجَلُ فَيُكْتَبُ كَذَلِكَ فِي بَطْنِ أُمِّهِ