Sahih al-Bukhari 6595

Sulayman ibn Harb narrated to us; Hammad narrated to us, from Ubaydullah ibn Abi Bakr ibn Anas, from Anas ibn Malik, may Allah be pleased with him, from the Prophet, peace and blessings be upon him, who said: ‘Allah appoints an angel over the womb. The angel says, My Lord, a drop of fluid; My Lord, a clinging clot; My Lord, a lump of flesh. When Allah wishes to complete its creation, the angel asks whether it is male or female, wretched or blessed, and what its provision and lifespan will be. All of that is written while it is in its mother's womb.’