Chapter 47: The Book of Destiny
Hadhaifa b. Usaid Ghifari, a Companion of Allah' s Messenger (ﷺ), reported it directly from Allah' s Messenger (may peace upon him). as he said: There is an angel who looks after the womb when Allah decides to create any- thing after more than forty nights are over; the rest of the hadith is the same.
Sahih Muslim 2645d