Sahih al-Bukhari 3333
صحيح البخاري#3333SahihNarrated Anas bin Malik: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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 60:8