Each one of you in creation amasses in his mother's womb [in the form of a drop] for forty days; then he becomes a blood clot for the same period; then he becomes a lump of flesh for the same period; then the angel is sent with a mandate [to write down] four things [for the child]: his sustenance, his term of life, his deeds, and whether he will be miserable or happy? -Bukhari, Sahih